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SJVDP LIBRARY 5&^2-^ 




DISSIPATION OF SOIL SELENIUM BY MICROBIAL 
VOLATILIZATION AT KESTERSON RESERVOIR 



Final Report 
December, 1988 



Prepared for the 



U.S. Department of the Interior 
Bureau of Reclamation 
2800 Cottage Way 
Sacramento, CA 95825 



4Jnder 

U.S. Bureau of Reclamation 
Contract No. 7-FC-20-05240 



by 



Department of Soil and Environmental Sciences 
University of California 
Riverside, CA 92521 



CONTENTS 



EXECUTIVE SUMMARY 



Page 
xiv 



CHAPTER 1. INTRODUCTION 1-1 

Scope of Project 1-1 

Background 1-2 

Objectives 1-5 

CHAPTER 2. ACCELERATED RATES OF SELENIUM VOLATILIZATION. ... 2-1 

Introduction 2-1 

Materials and Methods 2-2 

Method of Assay 2-3 

Isolation of Selenium Biomethylating 

Microorganisms 2-5 

Fungal inoculum 2-5 

Results 2-6 

Factors Affecting Selenium Methyl ati on 

in Soil 2-6 

Fungal inoculum 2-6 

Selenium concentration 2-6 

Carbon amendments 2-10 

Discussion 2-14 

CHAPTER 3. ENVIRONMENTAL FACTORS AFFECTING 

BIOMETHYLATION OF SELENIUM 3-1 

Introduction 3-1 

Materials and Methods 3-3 

Reagents 3-3 

Buffer 3-5 

Method of Assay 3-5 

Gas Chromatography-Mass Spectrometry .... 3-6 
Factors Affecting Biomethylation of 

Selenium 3-6 

pH 3-6 

Moisture 3-7 

Temperature 3-7 

Organo-selenium substrates 3-8 

L-Methionine 3-8 

Carbohydrates 3-8 

Proteins 3-9 

Results 

Factors Affecting Biomethylation of 

Selenium 3-9 

pH 3-9 

Moisture 3-9 

Temperature 3-13 

Organo-selenium substrates 3-15 



Page 

L-Methionine 3-17 

Carbohydrates 3-17 

D-Galacturonic acid 3-21 

Proteins 3-21 

Discussion 3-24 

CHAPTER 4. TOXICITY AND FATE OF ALKYLSELENIDES 

IN THE ENVIRONMENT 4-1 

Toxicity ..... 4-1 

Fate of Gaseous Selenium 4-2 

CHAPTER 5. PHYSICOCHEMICAL PROPERTIES OF DIMETHYLSELENIDE 

AND DIMETHYLDISELENIDE 5-1 

Introduction 5-1 

Materials and Methods 5-3 

Vapor pressure 5-3 

Solubility 5-3 

Results 5-6 

Vapor pressure 5-6 

Solubility 5-9 

Heat of vaporization 5-9 

Discussion 5-12 

CHAPTER 6. DESCRIPTION OF FIELD EXPERIMENT 6-1 

Date of Applications 6-1 

Pond 4 Main Experiments % 6-5 

Treatment details 6-5 

Pond 4 Side Experiments 6-5 

Treatment details 6-6 

Pond 11 Main Experiments 6-6 

Treatment details 6-6 

Pond 11 Side Experiments 6-7 

Treatment details 6-7 

Rototilling 6-8 

Irrigation 6-8 

San Luis Drain Experiment 6-9 

Treatments 6-11 

Soil and Gas Sampling 6-11 

Profile sampling 6-11 

Soil surface sampling 6-11 

Gaseous selenium sampling 6-11 

Pond 4 6-11 

Pond 11 6-12 

San Luis Drain sediment 6-12 

CHAPTER 7. MONITORING VOLATILE SELENIUM 

EMISSION IN THE FIELD 7_1 

Apparatus 7_1 



n 



Page 

Background Levels 7-4 

Shipping of Samples 7-4 

Analysis 7-4 

Method Development 7-5 

Boiling 7-5 

Recovery 7-5 

* 

CHAPTER 8. EMISSION RATES OF VOLATILE SELENIUM 

IN THE FIELD 8-1 

Pond 4 8-1 

Temperature 8-1 

Irrigation and tillage 8-3 

Cattle manure 8-3 

Barley straw plus N 8-7 

Molasses 8-7 

Cattail straw plus N 8-7 

Citrus pulp 8-11 

Citrus pulp + Zn + N 8-11 

Proteins 8-14 

Pond 11 8-17 

Temperature 8-19 

Irrigation and tillage 8-19 

Cattle manure 8-19 

Barley straw 8-23 

Citrus pulp 8-29 

Proteins 8-38 

San Luis Drain Sediment 8-43 

Sediment characterization 8-43 

Irrigation and organic amendments 8-43 

Influence of Temperature 8-46 

Discussion 8-47 

CHAPTER 9. CONTROLLED STUDIES IN MONITORING SELENIUM 
VOLATILIZATION FROM TREATED-KESTERSON 

SEDIMENTS 9-1 

Introduction 9-1 

Materials and Methods 9-2 

Soil incubation 9-2 

Soil amendments 9-3 

Determination of Se evolution 9-5 

Results 9-6 

Discussion 9-9 

CHAPTER 10. DISSIPATION OF SELENIUM FROM 

THE Ap HORIZON 10-1 

Soil Analysis 10-1 

Procedure 10-1 



m 



Page 

Quality assurance objectives for 

generation of data 10-2 

Selenium Distribution in Soil Profiles 10-5 

Biological Monitoring 10-14 

Spatial Varability 10-14 

Soil Selenium Removal from the Ap Horizon. . . . 10-27 

Pond 4 10-28 

Pond 11 10-38 

Statistical Relationships 10-50 

CHAPTER 11. VOLATILIZATION AS A BIORECLAMATION PROGRAM 11-1 

Factors Affecting Volatilization 11-1 

Irrigation equipment 11-3 

Quality of water 11-3 

Available Carbon Sources 11-5 

Cost of Equipment and Amendments 11-5 

Filling of Ephemeral Pools 11-8 

ACKNOWLEDGEMENTS 12-1 

REFERENCES R-1 

APPENDIX A. RAW DATA A-1 

APPENDIX B. TOXICITY OF INHALED DIMETHYLSELENIDE 

IN ADULT RAT B-1 

APPENDIX C. QUALITY ASSURANCE/QUALITY CONTROL 

PROCEDURES C-1 

APPENDIX D. QUOTATION D-1 



IV 



LIST OF TABLES 

Page 

Table 2-1. Properties of soils used 2-3 

Table 8-1. Average background emission rates of 

gaseous selenium at Kesterson Reservoir 8-5 

Table 8-2. Amino acid composition of casein and 

gluten 8-18 

Table 8-3. Influence of specific treatments on 
volatilization of selenium from the 
San Luis Drain sediment 8-45 

Table 9-1. Organic materials used as soil amendments .... 9-4 

Table 9-2. Analysis of variance of cumulative selenium 
volatilization from Kesterson soil as 
affected by different amendments 9-8 

Table 10-1. Data quality objectives 10-2 

Table 10-2. Analysis of internal quality assurance 
samples to assess accuracy of analytical 
technique 10-4 

Table 10-3. Quality control of soil samples from 

Kesterson Reservoir 10-6 

Table 10-4. Profile distribution of selenium at 

Pond 4, Kesterson Reservoir 10-9 

Table 10-5. Profile distribution of selenium at 

Pond 11, Kesterson Reservoir 10-11 

Table 10-6. Means and standard deviations of 
individual soil sample data 
(mg Se kg-i soil) 10-25 

Table 10-7. Coefficients of determination for 
regression of pooled soil Se data 
versus time 10-29 

Table 10-8. Soil selenium removal rates in response 
to specific amendments added to Pond 4, 
Kesterson Reservoir 10-37 



Page 

Table 10-9. Soil selenium removal rates in response 
to specific amendments added to Pond 11, 
Kesterson Reservoir 10-49 

Table 10-10. Correlation matrix (r values) between 
soil Se depletion, gas emission, soil 
temperature, and time in Pond 4 10-51 

Table 10-11. Correlation matrix (r values) between 
soil Se depletion, gas emission, soil 
temperature, and time in Pond 11 10-52 

Table 11-1. Quality of water used for volatilization 

of selenium 11-4 

Table 11-2. Costs of amendments for Se volatilization 

as a bioremediation program 11-7 



VI 



LIST OF FIGURES 



Page 



Fig. 2-1. Selenium volatilization from native (non-sterile) 
and autoclaved Los Banos soil, upon inoculation 
with fungal isolates. Se(IV) addition, 100 mg 
kg-i. Equivalent C addition, 2 g kg-i. Sampling 
interval, 1 to 1.5 days. Data points represent 
the average of 3 replicates; bars represent 
standard errors 2-7 

Fig. 2-2. Volatilization of Se(IV) added to Los Banos, 
Panoche and Panhill soils. No C addition. 
Sampling interval, 1.5 to 3 days. Data points 
represent the average of 3 replicates; bars 
represent standard errors 2-8 

Fig. 2-3. Volatilization of Se(VI) added to Los Banos, 
Panoche, Panhill and Ciervo soils. No C 
addition. Data points represent the average 
of 3 replicates; bars represent standard errors. . . 2-9 

Fig. 2-4. Volatilization of Se(IV) added to Los Banos, 

Panoche and Ciervo soils. Equivalent C addition, 

2 g kg~i, repeated twice as indicated. Data 

points represent the average of 3 replicates; 

bars represent standard errors 2-11 

Fig. 2-5. Volatilization of Se(VI) added to Los Banos, 

Panoche and Ciervo soils. Equivalent C addition, 

2 g kg"^, repeated twice as indicated. Data 

points represent the average of 3 replicates; 

bars represent standard errors 2-12 

Fig. 3-1. Location of Kesterson National Wildlife Refuge 

(Merced County, CA) 3-4 

Fig. 3-2. Mass spectrum of dimethylselenide (DMSe) 3-10 

Fig. 3-3. Influence of soil pH on DMSe production 3-11 

Fig. 3-4. Influence of moisture content on DMSe production 

from soil 3-12 

Fig. 3-5. Influence of temperature on DMSe production 

from soil 3-14 

Fig. 3-6. Influence of organo-Se compounds on DMSe 

production from soil 3-16 



vn 



Page 

Fig. 3-7. Influence of L-methionine on DMSe production 

from soil 3-18 

Fig. 3-8. Influence of carbohydrates on DMSe production 

from soil 3-19 

Fig. 3-9. Influence of polysaccharides on DMSe production 

from soil 3-20 

Fig. 3-10. Influence of D-galacturonic acid on DMSe 

production from soil 3-22 

Fig. 3-11. Influence of protein sources (casein, albumin 

and gluten) on DMSe production from soil 3-23 

Fig. 5-1. Experimental apparatus used for vapor pressure 

determinations of DMSe and DMDSe 5-4 

Fig. 5-2. Vapor pressure of DMSe versus temperature 5-7 

Fig. 5-3. Vapor pressure of DMDSe versus temperature .... 5-8 

Fig. 5-4. Vapor density of DMSe in the headspace 
(41.235 mL) over Hg (100.000 mL) versus 
total DMSe added to the system 5-10 

Fig. 5-5. The relationship between vapor pressure of DMSe 

and DMDSe and the reciprocal of temperature. . . . 5-11 

Fig. 6-1. Layout of field plots in Pond 4, Kesterson 

Reservoir 6-2 

Fig. 6-2. Layout of field plots in Pond 11, Kesterson 

Reservoir 6-3 

Fig. 6-3. Location of site where the San Luis Drain 

sediment (SLDS) was collected 6-10 

Fig. 7-1. Apparatus used to monitor alkylselenide 

production in the field 7-2 

Fig. 7-2. Effect of time of duration in boiling for 

reduction of Se 7-6 

Fig. 7-3. Percent recovery of dimethylselenide in 

alkaline-peroxide traps 7-8 



vm 



Page 

Fig. 8-1. Soil temperatures recorded at Pond 4, 
Kesterson Reservoir from October, 1987 
to September, 1988 8-2 

Fig. 8-2. Influence of moisture on Se volatilization 

from Pond 4, Kesterson Reservoir 8-4 

Fig. 8-3. Influence of cattle manure on Se volatilization 

from Pond 4, Kesterson Reservoir 8-6 

Fig. 8-4. Influence of barley straw on Se volatilization 

from Pond 4, Kesterson Reservoir 8-8 

Fig. 8-5. Influence of molasses on Se volatilization 

from Pond 4, Kesterson Reservoir 8-9 

Fig. 8-6. Influence of cattail straw on Se volatilization 

from Pond 4, Kesterson Reservoir 8-10 

Fig. 8-7. Influence of citrus pulp on Se volatilization 

from Pond 4, Kesterson Reservoir 8-12 

Fig. 8-8. Influence of citrus + Zn + N on Se volatilization 

from Pond 4, Kesterson Reservoir 8-13 

Fig. 8-9. Influence of gluten on Se volatilization 

from Pond 4, Kesterson Reservoir 8-15 

Fig. 8-10. Influence of casein on Se volatilization 

from Pond 4, Kesterson Reservoir 8-16 

Fig. 8-11. Soil temperatures recorded at Pond 11, 
Kesterson Reservoir from October, 1987 
to September, 1988 8-20 

Fig. 8-12. Influence of moisture on Se volatilization 

from Pond 11, Kesterson Reservoir 8-21 

Fig. 8-13. Influence of manure (equiv. to 89 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-22 

Fig. 8-14. Influence of manure (equiv. to 41 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-24 

Fig. 8-15. Influence of manure (equiv. to 62 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-25 



IX 



Page 



Fig. 8-16. Influence of manure (equiv. to 137 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-26 

Fig. 8-17. Influence of manure (equiv. to 206 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-27 

Fig. 8-18. Influence of barley straw on Se volatilization 

from Pond 11, Kesterson Reservoir 8-28 

Fig. 8-19. Influence of barley straw + N (C/N = 5) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-30 

Fig. 8-20. Influence of barley straw + N (C/N = 10) on Se 
volatilization from Pond 11, Kesterson 
Reservoir. 8-31 

Fig. 8-21. Influence of barley straw + N (C/N = 20) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-32 

Fig. 8-22. Influence of citrus pulp (30 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-33 

Fig. 8-23. Influence of citrus pulp (9 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-34 

Fig. 8-24. Influence of citrus pulp (14 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-35 

Fig. 8-25. Influence of citrus pulp (20 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-36 

Fig. 8-26. Influence of citrus pulp (45 t/ac) on Se 
volatilization from Pond 11, Kesterson 
Reservoir 8-37 

Fig. 8-27. Influence of citrus + N on Se volatilization 

from Pond 11, Kesterson Reservoir 8-39 

Fig. 8-28. Influence of citrus + Zn on Se volatilization 

from Pond 11, Kesterson Reservoir 8-40 



Page 

Fig. 8-29. Influence of citrus + Zn + N on Se 

volatilization from Pond 11, Kesterson 

Reservoir 8-41 

Fig. 8-30. Influence of casein on Se volatilization from 

Pond 11, Kesterson Reservoir 8-42 

Fig. 8-31. Diurnal measurements of alkylselenide production 

in October 1987 8-48 

Fig. 8-32. Diurnal measurements of alkylselenide production 

from subplot 57 in February 1988 8-49 

Fig. 8-33. Diurnal measurements of alkylselenide production 

from subplot 58 in February 1988 8-50 

Fig. 8-34. Diurnal measurements of alkylselenide production 

from subplot 61 in February 1988 8-51 

Fig. 8-35. Diurnal measurements of alkylselenide production 

from subplots 54 and 63 in September 1988 8-52 

Fig. 8-36. Linear regression analysis of alkylselenide 
production in subplot 57 and atmospheric and 
soil temperature 8-53 

Fig. 8-37. Linear regression analysis of alkylselenide 
production in subplot 58 and atmospheric and 
soil temperature 8-54 

Fig. 8-38. Linear regression analysis of alkylselenide 
production in subplot 61 and atmospheric and 
soil temperature 8-55 

Fig. 9-1. Selenium volatilization from Kesterson soil 

(Pond 4) in response to different amendments . . . 9-7 

Fig. 9-2. Actual and temperature-standardized Se 

volatilization from Kesterson soil, after 

amendment with citrus pulp and Zn 9-12 

Fig. 10-1. Schematic representation of soil Se inventory 
data (individual samples) at Pond 4, Kesterson 
Reservoir 10-15 



xi 



Page 



Fig. 10-2. 

Fig. 10-3. 

Fig. 10-4. 

Fig. 10-5. 

Fig. 10-6. 

Fig. 10-7. 

Fig. 10-8. 

Fig. 10-9. 

Fig. 10-10. 

Fig. 10-11. 

Fig. 10-12. 

Fig. 10-13. 

Fig. 10-14. 

Fig. 10-15. 



Schematic representation of soil Se inventory 
data (individual samples) at Pond 11, Kesterson 
Reservoir 

Frequency distribution of soil Se inventory 
data (individual samples) at Pond 4, Kesterson 
Reservoir 

Frequency distribution of soil Se inventory 
data (individual samples) at Pond 11, Kesterson 
Reservoir 

Fractile diagrams for soil Se inventory data 
for individual and composite samples at Pond 4, 
Kesterson Reservoir 



Fractile diagrams for soil Se inventory data 
for individual and composite samples at Pond 11, 
Kesterson Reservoir 



Fractile diagrams of soil Se November (1987) 
data for individual and composite samples at 
Pond 4, Kesterson Reservoir 



Fractile diagrams of soil Se November (1987) 
data for individual and composite samples at 
Pond 11, Kesterson Reservoir 



Soil selenium removal rates in response to 
added moisture to Pond 4, Kesterson Reservoir. 

Soil selenium removal rates in response to 
barley straw to Pond 4, Kesterson Reservoir. . 

Soil selenium removal rates in response to 
cattle manure to Pond 4, Kesterson Reservoir . 

Soil selenium removal rates in response to 
citrus pulp to Pond 4, Kesterson Reservoir . . 

Soil selenium removal rates in response to 
citrus + Zn + N to Pond 4, Kesterson Reservoir 

Soil selenium removal rates in response to 
molasses to Pond 4, Kesterson Reservoir. . . . 



Soil selenium removal rates in response to 
cattail straw to Pond 4, Kesterson Reservoir . 



10-16 
10-18 
10-19 
10-21 
10-22 
10-23 

10-24 

10-30 
10-31 
10-32 
10-33 
10-34 
10-35 
10-36 



xn 



Page 

Fig. 10-16. Soil selenium removal rates in response to 

moisture to Pond 11, Kesterson Reservoir 10-39 

Fig. 10-17. Soil selenium removal rates in response to 

barley straw to Pond 11, Kesterson Reservoir . . . 10-40 

Fig. 10-18. Soil selenium removal rates in response to 

cattle manure to Pond 11, Kesterson Reservoir. . . 10-41 

Fig. 10-19. Soil selenium removal rates in response to 

citrus to Pond 11, Kesterson Reservoir 10-42 

Fig. 10-20. Soil selenium removal rates in response to 
barley straw (C/N = 5) to Pond 11, Kesterson 
Reservoir 10-43 

Fig. 10-21. Soil selenium removal rates in response to 

barley straw (C/N = 10) to Pond 11, Kesterson 

Reservoir 10-44 

Fig. 10-22. Soil selenium removal rates in response to 

barley straw (C/N = 20) to Pond 11, Kesterson 

Reservoir 10-45 

Fig. 10-23. Soil selenium removal rates in response to 
varying application rates of cattle manure 
(41, 62, 137 and 206 t/ac) to Pond 11, 
Kesterson Reservoir 10-46 

Fig. 10-24. Soil selenium removal rates in response to 
varying application rates of citrus pulp 
(9, 14, 20 and 45 t/ac) to Pond 11, 
Kesterson Reservoir 10-47 

Fig. 10-25. Soil selenium removal rates in response to 
citrus + Zn, citrus + N and citrus + Zn + N 
to Pond 11, Kesterson Reservoir 10-48 



xm 



EXECUTIVE SUMMARY 

Microbial production of alkylselenides is recognized as an 
important process affecting the mobility and toxicity of selenium (Se) 
in the soil environment. This microbial transformation links the 
global cycle of Se through production of dimethylselenide (DMSe) 
and minor quantities of dimethyldiselenide (DMDSe). Selenium is 
emitted into the atmosphere in substantial quantities in the vapor 
phase through high temperature (fossil fuel burning, industrial acti- 
vities [smelting], volcanism and burning vegetation) and low temperature 
processes (aerosol generation at the sea surface and biomethylation by 
soil and plants). On a global scale, between 30°N and 90°N, it is 
estimated that a total of 2700 to 9400 metric tons of Se per year are 
emitted from these sources. The soil microbial component in this 
estimate is 1300 metric tons per year. 

This study is a comprehensive investigation focusing on optimizing 
the dissipation of soil Se through microbial volatilization as a bio- 
reclamation technique to detoxify Kesterson Reservoir. Studies were 
conducted both in the laboratory and in the field. Recent work in this 
laboratory involved the development of a new effective method to monitor 
volatile Se as a microbial metabolite when soils were exposed to ^^Se. 
Labeled inorganic Se was applied to soil and the gaseous products were 
monitored in a continuous flow system, by using activated carbon traps 
and counting the recovered ''^Se. We found that the rate of Se 



XIV 



methylation is enhanced considerably upon incorporation of pectin. 
As much as 9% of the added Se was recovered in the volatile form in 
only 13 days of incubation upon treatment with pectin. The addition 
of trace elements such as molybdenum, mercury, chromium, and lead 
inhibits volatilization of Se while arsenic, boron (B), and manganese 
have little effect. The presence of cobalt, nickel and zinc (Zn) in 
soil at moderate to high levels can dramatically stimulate volatiliza- 
tion of Se, while high nitrogen (N) applications with added carbon (C) 
inhibit this reaction. Inoculation with isolates of Se methylating 
fungi, including Acremonium falciforme, Penicillium citrinum and 
Ulocladium tuberclatum , enhanced Se evolution in nonsterile and 
autoclaved soils. The fraction of added Se volatilized per unit time 
was dependent upon the Se level, soil series, Se species and C amend- 
ments. Without the addition of C, volatilization rates were up to an 
order of magnitude higher with selenite (Se[IV]) as the Se source, when 
compared to selenate (Se[VI]). Carbon addition in the form of pectin 
accelerated Se evolution 2- to 130-fold, which was more pronounced with 
Se(VI). Hence with C amendments, Se(VI) was volatilized almost as 
rapidly as Se(IV). With 3 pectin amendments over a period of 118 days, 
total Se volatilization ranged from 11.3 to 51.4% of the added Se. A 
minimum Se threshold for alkylselenide production was not found, 
applying Se additions as low as 10 ^g kg"^ soil. 

A study was conducted to determine the environmental factors 
affecting microbial volatilization of Se. A selenifenous soil 



XV 



collected from Pond 4, Kesterson Reservoir was assayed for DMSe produc- 
tion by incubating for up to 120 h at 22°C under various treatments. DMSe 
was determined by gas chromatographic analysis and unequivocally iden- 
tified by gas chromatography-mass spectrometry. The optimum buffer pH 
was found to be pH 8 which is within the same range as the Kesterson 
soils. The optimum moisture content appears to be at field capacity 
(-33 kPa, 2.5 pF). Warm temperatures enhance DMSe production (temp , = 
35°C). The methyl ating activity was approximately 17.8-fold greater 
at 35°C than at 5°C. The average Q,q was calculated at 2.60. 
Organo-Se as well as inorganic Se compounds are readily used as 
substrates for Se volatilization. Selenomethionine enhanced the 
methylation reaction much more (6.18-fold) than any other organo-Se 
substrates (e.g., selenoethionine, selenoguanosine, selenopurine, and 
selenourea). Specific carbohydrates and amino acids were found to 
stimulate DMSe production. Glucose, sucrose, maltose, fructose, 
cellobiose, chitin, galacturonic acid and methionine promoted volatile 
Se production. Among all the compounds tested, proteins (e.g., casein, 
albumin and gluten) enhanced biomethylation of Se more than any other 
treatment. Albumin (0.1 g C kg"-^ soil) applied to soil promoted the 
gaseous Se production 19.3-fold over the unamended moist control. 

*A study on the toxicity of inhaled DMSe was investigated with 85 
adult rats exposed to four concentration levels (0, 1607, 4499 and 8034 
ppm) for one hour. Not a single animal was killed by the gaseous DMSe. 



XVI 



After exposure, the animals were observed for a one-week period for 
clinical abnormalities. All the animals appeared normal during the 
7-day observation period. The exposed and control rats were sacrificed 
and their major tissues and organs were examined. There was a slight 
increase in the lung weight after one day of exposure. There was also 
slight injury to the spleen with increased spleen protein and RNA at the 
highest concentration (8034 ppm) but normal recovery was noted later. 
This effect appeared to be more of an irritation rather than an injury. 
Histological sections of the lung, liver, spleen, thymus, lymph nodes, 
pancreas and adrenal gland were examined and appeared normal. Protein, 
DNA and RNA content of the liver and lungs were measured to quantify the 
minor inflammation response. Changes in the liver and lungs appeared to 
be minor, and after 7 days the organs had completely recovered. The Se 
content in the lungs and serum were slightly elevated at day one post- 
exposure, but it appears that the half -life of DMSe is very short and 
the compound is eliminated mainly via the lung. The data indicate that 
inhaled DMSe vapor is nontoxic to the rat. 

The volatility of alkylselenides depends on their vapor pressures, 
along with their water solubility, soil adsorptivity and stability, and 
the existing wind speed and air turbulence. Studies were conducted to 
determine the vapor pressure of DMSe and DMDSe and the solubility of 
DMSe. The vapor pressure was determined by the isoteniscope method, 
while solubility was calculated from the headspace vapor density. The 
vapor pressure for DMSe and DMDSe at 25°C was calculated at 31.5 and 
0.37 kPa, respectively. The vapor pressure of DMSe is approximately 



XVI 1 



five times that of ethanol and one-half that of ether. Raising the soil 
temperature from 10°C to 25°C approximately doubles the vapor pressure 
of DMSe, while raising the temperature from 25°C to 40°C doubles it 
again, i.e., produces a vapor pressure four times as high as at 10°C. 
Obviously, the Se field emission rates are highly dependent on soil and 
air temperature. The heat of vaporization for DtlSe and DMDSe is 31.9 and 
74.9 kj mol"\ respectively. The solubility of DMSe was calculated at 
0.0138 g mL"^ HjO at 25°C. Being highly soluble in HjO, DMSe may be 
retained by water films which would decrease its rate of dissipation. 
This obstacle could possibly be overcome by certain management schemes 
such as irrigating with wetting and drying cycles. Further work is 
being conducted to determine the solubility of DMDSe. 

Field experiments were initiated to assess microbial volatiliza- 
tion of Se at Kesterson Reservoir on July 28, 1987. Two sites were 
selected, one in Pond 4 and the other in Pond 11 to represent a highly 
and a less severely contaminated area, respectively. The soil at Pond 
11 contained considerably less Se (1.17 to 8.63 mg kg"^) than at Pond 4 
(10 to 209 mg kg"^). The soil was disked, rototilled, and the plots 
were staked out into sub-plots. The amendments included citrus pulp 
(30-35% in pectin), cattle manure, barley straw, and later, proteins 
(albumin, casein and gluten). Some of the subplots were fertilized 
with nitrogen (NH^NOg and [NH^ljSOi^) and the micronutrient, Zn (ZnSOl,). 
All plots were rototilled to 6" within 24 h after application of amend- 
ments, and every other week during the winter if weather permitted. 



XVI n 



During the summer months the plots were rototilled once a week. Irri- 
gation was conducted daily until October 22, 1987. After that, rainfall 
interrupted the irrigation schedule until May, 1988. Water was applied 
just to keep the upper few inches of soil moist, but not to transport 
the soluble Se below the surface layer (Ap [plow layer]). , 

On September 19, 1988 a pilot study on the San Luis Drain sediment 
was initiated at Kesterson Reservoir (Pond 4). The sediment was well- 
mixed, air-dried and placed approximately 6" high in S'xS'xl' open 
PVC containers. Similar treatments as described previously were applied 
to this sediment. 

Selenium volatilization was monitored in the field with a flux chamber 
system as designed by Lawrence Berkeley Laboratory (LBL). The equipment 
required for this operation consists of the gas sampling chambers, a 
compressor vacuum pump, gas washing bottles (40-60 \in porosity), a gas 
manifold and vinyl and surgical tubing. A vacuum connected to the mani- 
fold pulled the air above the soil into a trap of alkaline peroxide at 
2 L min"-^. The trapped volatile Se was oxidized to Se(VI) and analyzed 
by atomic absorption spectrometry /hydride generation. Results are 
reported as volatile emission rates expressed in ^g Se m"^ h"^. 

Emanation of volatile Se was monitored in the field at Pond 4, Pond 11 
and the San Luis Drain experiment. Seasonal and daily variation in micro- 
bial volatilization of Se was evident. Overall the highest emission rates 
were recorded in the summer months corresponding to the high soil tem- 
peratures. Less volatile Se was produced in the fall and winter months 
(Sept. -Mar. ). Average non-treated background emissions of volatile 



xix 



Se ranged from 0.82 to 10.08 (avg. = 3.53) ^g m"^ h"^ in Pond 4 and not 
detectable to 3.33 (avg. = 1.04) ^g m"^ h"^ in Pond 11. Moisture was 
definitely a limiting factor for volatilization of Se since the moist- 
only subplots (without C amendments) in Pond 4 had emission rates as 
high as 167 pg m"^ h~^. Treatments applied at Pond 4 promoted volatili- 
zation of Se in the following order: citrus + Zn + N (avg. yearly 
emission flux = 154 yg m"^ h~^) > casein (134) > gluten (90) > citrus 
(61) > moist (27) > molasses (24) > straw + N (23) > cattle manure (18) > 
cattail straw + N (13). The highest emission rate was recorded on 
August 8, 1988 at 808 ^g m"^ h"^ (subplot 63 [citrus + Zn + N]) in 
Pond 4. This treatment enhanced volatilization 229-fold over the 
background level. Since Pond 11 has one-tenth the Se content (median, 
3.75 mg Se kg"^) of Pond 4 (median, 39 mg Se kg~^) the emission flux 
was expected to be an order of magnitude less. The volatile Se emission 
rates with the moist-only subplots averaged 2.23 yg m'^ h"^. The only 
amendments that appreciably enhanced alkylselenide production in Pond 11 
over the moist-only subplots were citrus (2.0-fold), gluten (4.7-fold) 
and casein (13.5-fold). 

The San Luis Drain experiment has just recently been initiated and 
so far includes only 3 gas sampling periods. The straw + N amendment 
was the only treatment that inhibited Se volatilization (55% inhibi- 
tion). The protein amendments were the most stimulatory compared to the 
moist-only treatments: albumin (2.1-fold) > gluten (1.8-fold) > cotton- 
seed meal (1.7-fold) and casein (1.7-fold). 



XX 



The diurnal activity of volatile Se production indicated that this 
microbial transformation is highly dependent on temperature. The peak 
of volatile Se emission was always detected in mid-afternoon. There 
was a close relationship between volatile Se produced and the atmos- 
pheric and soil temperature. Seasonal cycle and temperature coefficient 
data indicate that Se emission rates are optimum during the spring and 
summer months with warmer temperatures. 

The field emission data may be an overestimate of the actual Se 
loss to the atmosphere because of i) some of the gaseous Se could 
have been taken up outside the periphery of the chamber upon lateral 
flow beyond the sampling area, ii) the forced flow of soil gas may 
have interfered with the natural resorption of DMSe, and iii) 24-h 
average emission readings would be less than mid-day readings because of 
the cooler temperatures at night. However, recovery of DMSe with direct 
injection into the sampling device in the field gave a recovery of only 
18.4% which could be attributed to sorption to the sampling chamber or to 
the soil. Attempts are currently being made to use passive activated C 
traps to capture the alkylselenides released in the field with long-term 
monitoring (2-3 days). 

We have conducted a simultaneous investigation at UCR (greenhouse 
study) which utilizes the same soil and treatments (plus several new 
amendments) as described in the field study. Volatile Se was trapped 
on activated C in a closed system to prevent gas loss and ensure high 
recovery (80%). Among the treatments tested, grape pomace inhibited vola- 
tilization, while chitin and straw had little effect. Pectin began to 



XXI 



promote volatilization only after its second application. Amendnents 
with cattle manure, citrus, citrus + Zn + N (with and without the 
combination of A. falci forme ) enhanced volatilization approximately 
2.8- to 3.5-fold over the control. Overall, the best amendment was 
citrus plus Zn stimulating volatilization 5.3-fold over the control. 
After 198 days of incubation, approximately 32% of the native Se was 
lost through volatilization compared to 6% with the unamended moist 
control. There was strong evidence that the addition of N upon C 
addition inhibits volatilization of Se in this study. Further work has 
been initiated (9/23/88) to test the influence of proteins (gluten, 
casein, cottonseed meal, soybean meal and safflower meal) and of native 
vegetation ( Distichlis spicata [saltgrass], Bassia hyssupifol ia , 
Atriplex patula and Typha domingensis ) on volatilization of Se from 
Kesterson sediments under these controlled conditions. 

Soil samples were collected during the field experiment on a 
monthly basis when weather permitted to monitor Se depletion through 
microbial volatilization. The quality assurance objectives for measure- 
ment of soil Se data were expressed in terms of accuracy, precision, 
completeness, representation, comparability and detection limits. Split 
samples among the University of California, Riverside and California 
State University, Fresno showed excellent agreement (_f 20% RPD) in 
measurements of soil Se content in samples obtained from Kesterson 
Reservoir. Selenium distribution in soil profiles of Ponds 4 and 11 
indicated that approximately 80% of the total Se in Pond 4 and 92% in 
Pond 11 occurs within the upper 6" of the soil profile. 



xxi 1 



Attempts were made to collect small fauna (mainly insects) in and 
around our plots, but under volatilization management insects seem to 
be very scarce. Frequent rototilling most likely disrupts the insect 
habitats and lowers their population. 

The spatial distribution of Se was studied on an 80- and 150-point 
grid in Pond 4 and 11, respectively. Fractile diagrams of individual 
soil Se data were constructed assuming normal and In normal distribu- 
tion. The Se inventory data followed a In normal distribution, but 
with time and frequent rototilling (mixing action) a normal distribution 
was approached. After 3 months of soil management, the standard 
deviations of the soil data were reduced roughly 50% in Pond 4 and 11. 
The physical effect of rototilling, which should be considered as a 
treatment by itself, removed the "hot spots", i.e., dangerously high Se 
levels, by distributing the Se evenly. 

Composite soil samples from each subplot were analyzed for total 
Se on a monthly basis during the course of our field study. Because 
of the high initial differences among replicates (subplots) of each 
treatment, the data had to be scaled using the initial (September) 
values of each subplot. Soil Se values from each subplot were expressed 
in percent of the initial value, pooled for each treatment and plotted 
versus time. The soil data seem to best fit a linear relationship of 
the initial rates of a first-order decay during this 10-month field 
study as opposed to polynomial, logarithmic and exponential. Treatments 
were ranked by soil Se depletion rates (% per month) in Pond 4 as follows; 
follows: citrus + Zn + N (2.77) > moist (2.58) > citrus (2.14) > straw 

xxi i 1 



(1.49) > manure (1.19). In terms of fit with the linear regression 
analysis, the following treatments were significant at the i) 99.9% 
level (moist and citrus), ii) 99% level (citrus + Zn +N), and iii) 95% 
level (straw). In Pond 11, the moist-only treatment showed a consider- 
able drop in Se content (22%) in the Ap horizon over a 10-month period. 
None of the other treatments led to any higher rates of soil Se removal 
than moisture alone; however, the application of proteins may show a 
substatial decrease in the residual Se as the study proceeds. Overall, 
the soil Se depletion data indicate that there is considerable dissipa- 
tion of Se from the Ap horizon. This diminishing Se could partially be 
attributed to other factors in addition to volatilization such as 
diluting the Se content in the Ap horizon with repeated rototilling and 
irrigation may have leached some of the soluble Se into greater depths. 
However, if leaching was a contributing factor, this was not evident 
until the wet season of the winter months (6 months after the initiation 
of the field study). Although the soil Se depletion data show a steady 
decline in Se content in the Ap horizon throughout the 10-month sampling 
period, attempts were not made to calculate mass balances. Further work 
is continuing in determination of the fate of the Se inventory. 

Factors which were identified to govern volatilization include 
available C sources, aeration, moisture, high temperatures and specific 
activators (e.g., Zn and Co). Disking in the native vegetation was shown 
to promote volatilization as long as the soil was kept moist. Frequent 
tillage is needed to support aerobic soil fungi, allow good soil 
porosity to facilitate diffusion of the alkylselenide gas and break any 

xxiv 



crust that may form as a result of sprinkler irrigation. Irrigation 
with wetting and drying cycles is recommended to release the organic- 
bound Se to the methylating organisms. Irrigation water should be 
applied to moisten the upper few inches of soil, otherwise the Se may 
be transported out of the surface layer making it unavailable for 
volatilization. The irrigation water quality required for this process 
was investigated. It was found that saline water (7.5 dS m' ^) high in 
boron (3.87 mg L"^) had little effect on Se volatilization under short- 
term incubation. Among all treatments, citrus + Zn and protein sources 
(e.g., cottonseed meal) appear to promote volatilization of Se in the 
field more than any other treatment. However, the availability of 
water appears to be the most limiting factor for methylation of Se. 
During the wet season, ephemeral pools at Kesterson Reservoir 
were considered to be a threat to the biota. As a means to correct 
this problem, much of these ephemeral pool areas have been filled in. 
Since much of the seleniferous sediment is now buried (6" to 8'), 
volatilization may not be the most effective technique since it is 
only applicable to the Ap horizon. Cultivated vegetation may be needed 
to extract Se at greater depths. Crop residues could be incorporated 
into the soil and provide additional C to stimulate volatilization. In 
addition, some higher plants are known to volatilize Se. At this time, 
the field results indicate that microbial volatilization is an effec- 
tive method to dissipate Se from the Ap horizon but not within a 2-year 
period as ordered by the State Water Resource Control Board. 



XXV 



1-1 



CHAPTER 1 
INTRODUCTION 

Scope of Project 

Terrestrial ecosystems are inhabited by a diverse group of 
microorganisms (e.g., bacteria, actinomycetes, fungi and yeast). These 
organisms are in a dynamic state in which their population may increase 
in size or decline depending upon their surrounding environment. Soil 
fungi make up a relatively large portion of the soil biomass. The 
fungal population and composition varies with major external factors 
such as organic sources, pH, moisture, aeration, temperature, season 
of the year and soil fertility. Some of these soil fungi are capable 
of converting trace elements (e.g., arsenic, antimony, mercury, tin, 
lead, tellurium and selenium) into methylated species. 

It has been recognized for some time that seleniferous soils may 
retain much less soluble selenium (Se) in their surface layer than their 
respective subsurface horizons in the soil profile. This loss has been 
proposed to be a result of volatilization or evaporation of Se to the 
atmosphere. Experiments with pure cultures of fungi, and with soil have 
demonstrated that volatile Se compounds can be produced from inorganic 
Se salts and several organo-Se compounds. However, until recently, this 
natural discharge from soil was considered to occur at insignificant 
rates. Our studies at the University of California, Riverside have shown 
that under the optimum environmental conditions soil fungi can remove 



1-2 



high levels of Se to such an extent that the biological process can 
be manipulated as an in situ bioreclamation technique to detoxify the 
environment. Microbial volatilization of Se is one of the few cleanup 
methods that can permanently remove Se rather than immobilizing it. The 
primary product, evolved is dimethylselenide (DMSe) which is much less 
toxic than other forms of Se. With proper management techniques, this 
biological transformation can be enhanced over 200-fold. Factors 
affecting this process include: an adequate carbon source, aeration, 
moisture, temperature and the presence of certain activators. 

Our second stage of research links the basic and applied studies 
through the use of field tests to confirm the laboratory work at two 
sites (Ponds 4 and 11) located at Kesterson Reservoir. Volatilization 
rates of Se were measured in the field along with the removal of resi- 
dual Se in soil subjected to selected treatments with time. Under 
intense management conditions, we "landf armed" the indigenous soil 
fungi to detoxify their surrounding environment of Se. 

Background 

Soil microorganisms have been known for several decades to have the 
ability of converting soil Se into volatile, gaseous forms (Abu-Erreish 
et al . , 1968; Doran and Alexander, 1977; Karl son and Frankenberger, 1988b) 
The main Se species evolved from Kesterson soil is DMSe, with very small 
quantities dimethyldiselenide (DMDSe) also being produced (Karlson and 
Frankenberger, 1988a). The alkylselenides have high vapor pressures, 
and thus are readily dispersed into the atmosphere, and thereafter 
diluted in the air. In addition, DMSe has a relatively low toxicity 



1-3 



threshold. For example, the LD^q (lethal dose) for selenite (SeCiV]) is 
is 3 mg per kg body weight (rat), while for DMSe it is 2200 mg per kg 
(McConnell and Portman, 1952; Franke and Moxon, 1936). In the vaporized 
form, DMSe is nontoxic to the rat (Appendix B). 

Biogenic Se volatilization is an important link in the global cycle 
of this element (Craig, 1986). It is estimated that in the northern 
hemisphere alone, approximately 5,000 to 10,000 metric tons of Se 
are emitted into the atmosphere annually, more than one-quarter of which 
originates from soils and plants (Ross, 1984). For comparison, the total 
amount of Se in the surface soil at Kesterson is approximately 6 metric 
tons. Gaseous Se is recycled to the earth's surface by dry and wet 
deposition in the form of Se(IV) (Ross, 1984). The residence time of 
atmospheric Se is approximately 9 days. Typical Se concentrations in 
rain water and snow range between 0.5 and 1.5 yg L"^ (Ross, 1984). 

Only recently has a thorough investigation been made of the 
factors affecting alkylselenide production from soil (Karlson and Fran- 
kenberger, 1988b). Karlson and Frankenberger (1988a) developed an 
effective method to monitor volatile Se as a microbial metabolite when 
soils were exposed to labeled inorganic Se (^^Se). Some of the factors 
affecting volatilization included carbon sources, activators, tempera- 
ture, moisture, and aeration (Karlson and Frankenberger, 1988b). Marked 
acceleration of this process was observed upon the addition of specific 
carbon sources in short-term experiments with high levels (100 mg kg" ^ 
soil) of Se(IV) and selenate (Se[VI])-''^Se as a Se source. The rate 
of methylation was increased dramatically upon incorporation of 



1-4 

pectin. Among the carbon compounds tested (galacturonic acid, glucuro- 
nic acid, cellubiose, cellulose, pectin, glucose, and starch), pectin 
stimulated the reaction more than any other treatment. As much as 9% 
of the added Se was recovered in the volatile form in only 13 days of 
incubation upon treatment with pectin. Slight stimulation of Se vola- 
tilization was also observed upon the addition of plant residues. 

Volatilization rates tend to decrease as carbon becomes depleted, 
but increase again upon carbon reload (Karl son and Frankenberger, 1988b), 
The addition of molybdenum, mercury, chromium, and lead at high levels 
greatly inhibits Se volatilization, while arsenic, boron, and manganese 
has little effect. The presence of cobalt (Co), zinc (Zn), and nickel 
(Ni) (25 mmol kg"^) increased Se volatilization rates over 300% (Karlson 
and Frankenberger, 1988b). After 37 days of incubation, recovery of 
added Se(IV) as DMSe was as high as 34, 30, and 23 percent with Co, Zn, 
and Ni ,• respectively, applied along with carbon amendments. Low levels 
of nitrogen in the presence of added carbon slightly enhanced alkyl- 
selenide production, while relatively high levels of N with C inhibit 
this microbial reaction. Evolution of volatile Se appears to be optimum 
under aerobic conditions, with the soil water content at field capacity. 

The primary organisms involved in volatilization of Se appear to 
be fungi. Scopulariopsis brevicaulis was the first reported organism 
to convert Se(IV) and Se(VI) into DMSe (Challenger and North, 1934). 
Since then a number of other fungi and bacteria have been reported to 
have the capacity to form DMSe from inorganic Se. It is believed that 
this transformation is a detoxification mechanism enabling these 



1-5 



organisms to tolerate high levels of Se. Both inorganic and organic 
Se compounds can be methylated into the gaseous product. 

Objectives 

The primary objective of this study was to identify the optimal 
soil management conditions that accelerate microbial volatilization of 
Se from soil. The supporting objectives are as follows; 

1. To determine the influence of different carbon amendments, 
interaction with N fertilizer and the effect of trace elements on Se 
aklylation. 

2. To identify soil microorganisms which are active in Se vola- 
tilization. 

3. To verify if Se(IV) and Se{VI) are equally effective as sub- 
strates for the methylation reaction, when added at comparable concen- 
trations. 

4. To determine if there is an optimum inorganic Se concentration 
for volatilization. 

5. To determine if there is a minimum threshold concentration of 
inorganic Se below which volatilization does not occur. 

6. To investigate the sustainability of high volatilization rates 
under long-term conditions. 

7. To determine the optimum parameters in terms of pH, moisture 
content, temperature, organo-Se substrates, carbohydrates and proteins 
on biomethylation of Se. 



1-6 



8. To evaluate the acute toxicity of inhaled DMSe vapor to the rat, 

9. To deterinine the vapor pressure and solubility of DMSe as a 
basis for an understanding of its interaction with air and water. 

10. To monitor emission rates of volatile Se in the field at 
Kesterson Reservoir when treated with various amendments. 

11. To determine Se volatilization rates from Kesterson sediments 
under controlled conditions and compare them with field emission 
rates. 

12. To determine the soil distribution of Se available for methyla- 
tion. 

13. To monitor the depletion of residual soil Se at Kesterson 
Reservoir when treated with various amendments. 



2-1 



CHAPTER 2 



ACCELERATED RATES OF SELENIUM VOLATILIZATION 



INTRODUCTION 

Conversion of selenium (Se) to volatile organic forms has been 
recognized as a widespread soil microbial process (Abu-Erreish et al . , 
1968; Doran and Alexander, 1977). The volatile Se species evolving from 
soils include dimethyl selenide (DMSe), dimethyldiselenide (DMDSe) , and 
possibly dimethyl selenone (Reamer and Zoller, 1980). Other species, 
e.g., diethyl selenide, could also possibly be produced. The dominant 
organisms producing alkylselenides have been identified as soil fungi 
(Fleming and Alexander, 1972; Barkes and Fleming, 1974); however, 
bacteria have also been reported (Doran, 1982). Conversion of a 
non-volatile inorganic element to a volatile species is an important 
factor with regards to the mobility and toxicity of the element, and 
constitutes an important link in its geochemical cycle (Craig, 1986). 

Only recently, the environmental factors affecting alkyl selenide 
production have been investigated (Karlson and Frankenberger, 1988b). 
Possibilities for a marked acceleration of the process by addition of 
specific carbon (C) sources were observed in short-term experiments 
with high levels (100 mg kg"^ soil) of Se(IV) as the Se source. Earlier 
findings (Ganje and Whitehead, 1958) indicated that Se evolution was 



2-2 



not dependent on whether Se(IV) or Se(VI) was supplied as the Se source. 
However, the comparison was not performed at equal Se concentrations. 
To our knowledge, the dependence on Se substrate levels has not been 
investigated with the exception of a study on the fate of trimethyl- 
selenonium (Olson et al . , 1976), which is not a common species in 
Se-contaminated soils. 

The primary objectives of this work were to i) identify soil 
microorganisms which are active in Se volatilization, ii) verify 
if Se(IV) and Se(VI) are equally effective as substrates when added at 
comparable concentrations for the methylation reaction, iii) determine 
if there is an optimum inorganic Se concentration for volatilization, 
iv) determine if there is a minimum threshold concentration of inorganic 
Se below which volatilization does not occur, and v) investigate the 
sustainabil ity of high volatilization rates under long-term conditions. 



MATERIALS AND METHODS 

The soils used throughout this study (Table 2-1) were air-dried sur- 
face samples (0-15 cm) of Los BaPios clay loam (fine montmorillonitic, 
thermic Typic Haploxeralf ) , Panoche clay loam (fine-loamy mixed, cal- 
careous, thermic Typic Torriorthent) , Panhill clay loam (fine-loamy, 
mixed, thermic Typic Haplargid), and Ciervo clay (fine montmorillonitic, 
calcareous, thermic Typic Torriorthent) that had been collected from the 
Panoche fan, a known Se-problem area on the west side of the San Joaquin 



2-3 



Table 2-1. Properties of the soils used. 





Los Banos 


Panoche 


Panhill 


Ciervo 


pH 


7.96 


8.05 


7.81 


8.13 


Organic C, g kg"! 


9.67 


9.77 


8.34 


4.71 


Total N, mg kg-i 


957 


980 


667 


647 


Total Se, yg kg-i 


216 


994 


311 


691 



Valley, CA. Soils were sieved (2-mm) and stored at 4°C for up to 6 
months prior to use. Where applicable, soil samples were autoclaved 
twice in a 2-day interval for 30 min at 12rc and 125 kPa. 

Method of Assay 

Alkylselenide production was measured using labeled Se, activated 
carbon traps and a continuous flow system as described previously 
(Karlson and Frankenberger, 1988a). Ten-g soil samples were brought 
up to and maintained at approximately -33 kPa (2.5 pF) and incubated 
at room temperature (23°C) in 250-mL Erlenmeyer flasks. Water-saturated 
air was used to sweep the headspace at 100 mL min"^. All treatments 
were performed in triplicate. Blanks were included for background 
determination. Carbon traps were exchanged and counted biweekly in a 
gamma counter. The radioactive element trapped by the activated carbon 
was positively identified as ^^Se by energy spectrum measurements and by 
half-life determination. Counts per minute were converted to quantity of 
Se volatilized by using internal standards and after subtracting 



2-4 



background values. Cumulative volatilization was calculated as the 
sum of individual measurements. Figures display the means of three 
replicates and standard errors thereof. Mass balance after experimen- 
tation accounted for 97.5% (+_1.2%) of the added label. The volatile 
products were eluted with methanol and identified by multiple ion 
monitoring using gas chromatography-mass spectrometry (GC-MS). The 
GC-MS was a VG analytical 7070 EHF high resolution mass spectrometer 
equipped with a 25 m CPS-2 capillary column, and with the following 
instrument settings: ionizing energy, 70 eV; instrument resolution, 
1000; source temperature, 200°C; accelerating voltage, 6000 V; carrier 
gas flow, 1 mL min"^ He; column temperature, 50 to 150°C; injector tem- 
perature, 150°C; monitoring interval 3 to 10 min. 

Selenium was added as NajSeOa or Na2SeO^ at 0.01 to 1000 mg kg" i 
soil, with a label activity of 0.5 mCi kg-i soil. NajSeOa snd 
Na2Se04 were analytical grade (Alfa Products, Danvers, MA). Na2''^Se0 3 

and Na2''5Se0i+ (radionuclide purity >99%) were obtained from Amersham 
(Arlington Heights, IL). The speciation of the two nonlabeled Se 
reagents was confirmed to be >99.9% pure by single-column ion 
chromatography (Karlson and Frankenberger, 1986a, b). The speciation of 
the two labels was tested by paper chromatography (Tuve and Williams, 
1961). Ascending chromatography was performed with Whatman 3M paper 
using isopropyl alcohol-formic acid-water, 70:10:20 (vol :vol :vol ) as 
the solvent system. The fraction of 75Se(IV) in the ■75Se(VI) label 
was <0.5% and that of 75Se(VI) in the 75Se(IV) label was <9.5% of the 
total 75se. 



2-5 

To study the effect of carbon on Se alkylation, pectin (Sunkist 
Growers, Corona, CA) dissolved in water was added to the respective 
samples at 2 g C equivalent kg-^ soil. Pectin had been described as 
the most effective C amendment in an earlier study (Karlson and 
Frankenberger, 1988b). Pectin applications were repeated every 35 to 
45 days, when alkylselenide production had leveled off. 

Isolation of Selenium Biomethylating Microorganisms 

Three microorganisms capable of producing alkylselenides were iso- 
lated from Los BaOos and Panoche soil by selective enrichment for Se 
tolerance using Sabouraud's dextrose agar (Difco, Detroit, MI) supple- 
mented with NaSeO (1 mg mL~M« Isolation of DMSe producing micro- 
organisms was conducted by measuring DMSe in the headspace of stoppered 
liquid cultures of the same medium by gas chromatography. Organisms 
that were active in this conversion were identified as Acremonium 
falci forme, Penici Ilium citrinum and Ulocladium tuberculatum . The gas 
chromatograph (Shimadzu) was equipped with a flame-ionization detector 
(FID) and a 3050 x 3.175 mm stainless steel column packed with 10% 
Carbowax 1000 on Chrom W-AW, mesh 60-80. The operating conditions 
consisted of the following: column temperature, 50°C; detector tem- 
perature, 105°C; carrier gas, N , 13 mL min"^; H flow, 50 mL min'^; 
air flow, 500 mL min"^; sample size, 1 cm^. 

Fungal Inoculum 

Autoclaved and non-sterile samples of Los Bafios soil were spiked 
with 100 mg kg"^ of labeled Se(IV), inoculated with the fungal isolates 



2-6 



(1.6 X 109 CFU kg-i soil) and incubated as described above. Inoculation 
was achieved by transfer of 1 cm^ discs cut out of agar plates overgrown 
with sporulating hyphae. Controls received sterile agar discs. All 
treatments of the inoculation study received galacturonic acid as a C 
source at 2 g C equivalent kg"^ soil. Galacturonic acid had been 
identified as another effective C amendment in an earlier study (Karl son 
and Frankenberger, 1988b). 

RESULTS 

Factors Affecting Selenium Methylation in Soil 

Fungal Inoculum 

The effect of inoculation with fungal isolates on Se volatili- 
zation is illustrated in Fig. 2-1. Application of A. falciforme to 
autoclaved soil restored almost 2/3 of its native Se volatilization 
capacity after 1 week of incubation. A similar effect, but to a lesser 
extent, was observed with P. citrinum and U. tuberculatum . After 
inoculation of one of the three isolates to non-sterile soil, the 
alkylselenide production rate increased by approximately 1.4-fold. 

Selenium Concentration 

Volatilization rates for added Se(IV) (Fig. 2-2) and Se(VI) 
(Fig. 2-3) were highly dependent on the level and species of Se 
substrate. In both cases, the highest rates (expressed in % of the 
added Se being volatilized) were often observed with the lowest Se 



L-l 



8 



7 - 



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LlI 6 
N 



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if) 

Q 

Q 3 

Q 

< 



O 2 

^0 



NON-STERILE: 

Control 

Rcifrinum 

A.falciforme 

U tuberculatum 

AUTOCLAVED: 

Control 

A. falciforme ^, ' 

U. tuberculatum /• ' .. • 

Rcitrinum // / 



^ 



/. 

f 



/ ^ 



/' 



//.. 

y ^ 
/^ .••• 




^•-« 



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4 5 

TIME (DAYS) 



8 



Fig. 2-1. Selenium volatilization from native (non-sterile) and 
autoclaved Los Banos soil, upon inoculation with fungal 
isolates. Se(IV) addition, 100 mg kg"^. Equivalent C 
addition, 2 g kg"^. Sampling interval, 1 to 1.5 days. 
Data points represent the average of 3 replicates; bars 
represent standard errors. 




2-8 







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LOS BANOS 



Se(VI) added, mg kg 



-I 



/ 



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N 



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o 
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30 
TIME (DAYS) 



Fig. 2-3. Volatilization of Se(VI) added to Los Banos, Panoche, 
Panhill and Ciervo soils. No C addition. Data points 
represent the average of 3 replicates; bars represent 
standard errors. 



2-10 



addition. For Los Banos, e.g., the average daily Se evolution was 0.35% 
at 5 mg Se(IV) kg-i and 0.03% at 1000 mg Se(IV) kg-i. Al kyl selenide 
production was substantially lower with Se(VI) as a substrate, than with 
Se(IV). Los Bahos only volatilized 0.13% of the added Se(VI) per day at 
5 mg kg"i. Similar relationships were observed with the other soils, 
except that they generally showed lower Se evolution rates. 

Carbon Amendments 

By amending Los Baflos soil with pectin, the observed relationship 
between Se level and volatilization rates was reversed (Fig. 2-4), Over 
a period of 118 days the average daily volatilization was 0.20% with 
0.01 mg Se(IV) kg-i soil, and 0.44% with 25 mg Se(IV) kg- 1 soil. How- 
ever, this reversal was not observed with the low producing Ciervo soil. 
Panoche soil, which was the intermediate producer in the experiments 
without C amendment, had its highest volatilization percentages (0.38% 
day-i) at 0.2 mg Se(IV) kg-i, with lower rates at higher and lower 
Se(IV) levels. Similarly, applying Se(VI) instead of Se(IV) (Fig. 2-5), 
the strongest relative volatilization potential was observed at 1 and 
0.2 mg Se(VI) kg-i in Los Banos and Panoche, respectively, and at 
0.04 mg Se(VI) kg'i in Ciervo. Although the 0.04 mg kg- i level is 
not illustrated in Fig. 2-5 for Los Bafios and Panoche, the data coincide 
with those points for 0.02 mg kg-i. 

Carbon amendments greatly accelerated volatilization rates in all 
cases, and it narrowed the gap in Se evolution rates between the 
different soils. At 5 mg Se(VI) kg-i soil without pectin, 4.0%, 0.3% 




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2-13 



and 0.04% of the added Se ions evolved from Los Banos, Panoche and Ciervo 
in 30 d, while 16.5%, 9.2%, and 5.3% was volatilized with pectin, 
respectively. The acceleration was most pronounced with Se(VI) as the 
Se source, to the effect that the rate differences in volatilization of 
Se(IV) versus Se{VI) almost disappeared upon the addition of C. During 
the first 30 days, the average daily Se emanation at 5 mg Se kg" ^ of 
Panoche soil without pectin was 0.08% with Se{I\/) and 0.01% with Se(VI); 
C addition increased these respective values to 0.34% for Se(IV) and 
0.30% for Se(VI). The rate increasing effect disappeared within 35 to 
45 days, but in most cases was observed again upon repeated pectin 
additions. The response to repeated C amendments was stronger for 
the higher Se levels. In particular with Se(VI) as the substrate, the 
rates following C reload were higher than the initial rates. 

Comparing the average volatilization rates for the first 30 days, 
the C amendment increased the rates from 1.8-fold to 4.4-fold in 
the presence of Se(IV) and from 2.0-fold to 131.5-fold with Se(VI). 
As a result of these dramatic rate increases, between 11.3 and 51.4% of 
the added Se was evolved within 118 days, with a total of 3 pectin addi- 
tions. The percentage of added Se volatilized was dependent on the soil 
series, Se species and Se level. The highest Se recovery through vola- 
tilization in the presence of Se(VI) was 23.0% for Ciervo soil at 0.04 
mg kg-i, 42.6% for Panoche at 0.2 mg kg-i, and 42.9% for Los Bailfos at 
1 mg kg~i. Upon the addition of Se(IV), recovery of alkylselenides was 
as high as 24.4% for Ciervo at 0.01 mg kg-i, 44.6% for Panoche at 0.2 mg 
kg-i, and 51.4% for Los Bafios at 25 mg kg-^. 



2-14 



DISCUSSION 

The effect of adding microbes adapted for Se volatilization to 
soil is illustrated by Fig. 2-1. The inocula consisted of fungal 
strains isolated from a seleniferous environment. Their competitive 
ability is demonstrated by the fact that they were able to accelerate 
Se volatilization in non-sterile soil. The relatively high Se level, 
and the addition of a complex C source such as pectin, supported their 
competitiveness. 

Experiments varying substrate concentration levels and speciation 
indicated that there is an optimum range for methyl ati on of Se in soils. 
This optimum appears to be at 5 to 20 mg kg"^ for Se(IV) and 0.025 mg 
kg" for Se(VI) without the addition of C. However, upon adding C, the 
optimum Se concentration range is 0.1 to 25 mg kg" ^ Se(IV) and 0.04 to 
1 mg kg" Se(VI). An inhibitory effect was observed with increasing Se 
concentration of Se(VI), but this was not apparent with Se(IV). 

The GC-MS analysis of carbon trap extracts confirmed that the 
volatile products were alkylselenides, mainly DMSe with small quantities 
of DMDSe. Similar observations have been noted by Doran and Alexander 
(1977). Reamer and Zoller (1980) identified DMSe, DMDSe and dimethyl 
selenone as products of soil and sewage sludge amended with Se(IV) and 
elemental Se. 

The observation that C amendments accelerated alkylselenide produc- 
tion among soils, is an indication that carbon is the major limiting 
factor. While the methyl ation pathway is uncertain, it is known that 
it involves reduction of Se and transfer of carbon groups, hence 



2-15 



requires energy at the expense of carbon. The importance of a C 
supply was evident by the rapid experimental disappearance of the 
amendments. The extent to which C addition cancels out the difference 
between Se(IV) and Se(VI) as a substrate may provide indirect informa- 
tion on the pathway of Se alkylation. Doran (1982) suggested that 
methylation of inorganic Se most likely involves the reduction of Se 
to the Se^~ species and subsequent methylation to form DMSe. Provid- 
ing Se(IV) instead of Se{VI) eliminates one reduction step, and hence 
could save a substantial amount of energy. Without a carbon supply, 
the reduction step from Se(VI) to Se(IV) might be the rate limiting 
step of the transformation. Even with C amendments, cumulative vola- 
tilization was consistently 5 to 15% lower with Se(VI). 

From the data presented here, we have not detected a minimum 
threshold concentration of soil Se below which volatilization would 
not occur. Even at extremely low Se levels (10 to 25 yg kg" ^ soil), 
Se(IV) and Se(VI) were readily converted to volatiles, even without C 
supplementation. This indicates that during soil genesis, biovolatili- 
zation could be a major factor for the Se depletion of topsoils. Under 
conditions of repeated C amendments, the time required to remove Se 
from soil would be greatly reduced. 



3-1 



CHAPTER 3 

ENVIRONMENTAL FACTORS AFFECTING 
BIOMETHYLATION OF SELENIUM 



INTRODUCTION 

Several studies with fungi, bacteria, plants and rats have shown 
that gaseous alkylselenides are produced from inorganic selenium (Se) 
and organo-Se compounds (Doran and Alexander, 1977b; Lewis et al . , 1974; 
Fleming and Alexander, 1972; Cox and Alexander, 1974). Also it is now 
well established that gaseous Se is released from soil (Abu-Erreish et 
al., 1968; Francis et al., 1974; Doran and Alexander, 1977a; Reamer and 
Zoller, 1980; Karlson and Frankenberger, 1988b, CPlapter 2 of this report). 
Volatilization of Se from soil is considered to be mainly a fungal 
transformation since numerous soil fungi are able to synthesize alkyl- 
selenides from inorganic Se (Challenger, 1945; Challenger and Charlton, 
1947; Fleming and Alexander, 1972; Cox and Alexander, 1974; Barkes and 
Fleming, 1974). Recently three genera of soil fungi were identified as 
active isolates in biomethylation of Se ( Acremonium falci forme, Penicil - 
lium citrinum, and Ulocladium tuberculatum (see Chapter 2). 

The predominant methylated Se species evolved from soil is dimethyl - 
selenide (DMSe), although dimethyldiselenide (DMDSe) and dimethyl selenone 



3-2 



(methylmethylselenite) have also been detected (Reamer and Zoller, 1980). 
Karlson and Frankenberger {1988a, b) characterized DMSe and DMDSe produc- 
tion by amending soil with labelled ''^Se(IV) and found enhanced emission 
rates upon the addition of plant materials, animal manures and certain 
carbohydrates. 

Selenium poisoning from agricultural waste water has been blamed 
for wildlife deaths and deformities at Kesterson Reservoir (Merced 
County, CA). Some approaches in reducing the Se concentrations have 
been proposed, but most of these tend to be costly and/or ineffectual 
(e.g., physical removal and disposal). One approach, which is based 
on the in situ biomethylation of Se, is being considered as an 
alternative (State Water Resources Control Board, 1988). Microbial 
volatilization of Se may be an effective detoxification process if the 
indigenous methylation rates can be maintained at a high rate 
(Frankenberger and Karlson, 1988a, b [patent pending]). 

The objective of this study was to determine the environmental 
factors which stimulate biomethylation of Se. By using a seleniferous 
soil obtained from Kesterson Reservoir naturally high in Se, attempts 
were made to optimize methylation of the native Se species comprised of 
both inorganic and bound-organic fractions. The parameters which were 
evaluated included: pH, moisture content, temperature and amendments 
with organo-Se substrates, L-methionine, carbohydrates and proteins. 



3-3 



MATERIALS AND METHODS 

The seleniferous soil used in this study was collected from Pond 4, 
Kesterson Reservoir (Fig. 3-1) and had the following properties: pH, 7.7; 
organic C (wet oxidation), 37.0 g kg~^; total nitrogen, 2.53 g kg~^; 
total Se, 60.7 mg kg"^; boron, 19 mg kg"^; electrical conductivity of 
a saturated extract (EC ) , 22.0 dS m~^; sodium absorption ratio (SAR), 
25; exchangeable sodium percentage (ESP), 26; and texture, 15% clay and 
58% sand. The soil was air-dried and sieved (2 mm) prior to use. 



Reagents 

Chitin, citric acid, D-fructose, D-fucose, D-galacturonic acid, 
D-rhamnose, seleno-DL-cystine, seleno-DL-ethionine, 6-selenoinosine, 
seleno-DL-methionine, 6-selenopurine, selenourea, ethionine, guanosine, 
inosine, DL-methionine and purine were obtained from Sigma (St. Louis, 
MO); boric acid, D-glucose, D-lactose, starch and D-sucrose from 
Mallinckrodt (Paris, KY); cellobiose, cellulose, and D-galactose 
from Difco (Detroit, MI); peptone from Nutritional Biochemicals 
(Cleveland, OH); L-cystine and egg albumin from J. T. Baker Chemical 
(Phillipsburg, NJ); D-maltose, sodium caseinate, tris(hydroxymethyl )- 
aminomethane, and urea from Fisher (Pittsburgh, PA); and DMSe from 
Strem Chemical (Newburyport, MA). 



3-4 i 



Modesto 





Fig. 3-1. Location of Kesterson National Wildlife Refuge (Merced 
County, CA). 



3-5 



Buffer 

Modified universal buffer (MUB) (0.17 M^) was prepared as described 
by Skujins et al . (1962). The stock solution consisted of 
tris(hydroxymethyl )aminomethane (12.1 g), maleic acid (11.6 g), citric 
acid (14.0 g) , boric acid (6.3 g), and 488 mL of 1 M NaOH, diluted to 
1 L with deionized water. Two hundred mL of the stock solution were 
titrated with 0.1 M^ HCl or NaOH to the desired pH and diluted to volume 
in a 1-L volumetric flask with deionized water. The MUB has a buffering 
range from pH 3 to 12. 

Method of Assay 

Routinely, DMSe production was monitored as follows: 25 g of soil 
were placed in a 125-mL screw-cap Erlenmeyer flask and treated with 12 
mL of deionized water. The soil was maintained at approximately -33 kPa 
(2.5 pF) unless otherwise noted. The flasks were sealed with Mininert 
valve-septa (Dynatech, Baton Rouge, LA) and incubated at room tempera- 
ture (22 +_ 2°C). DMSe was determined by gas chromatography by withdraw- 
ing 1-mL gas samples from the headspace above the soil with a gas-tight 
glass hypodermic syringe. The gas chromatograph (Shimadzu) was equipped 
with a flame-ionization detector (FID) and a 3-m 10% Carbowax 1000, 
Chrom W-AW 60/80 mesh column. The column temperature was 50°C. The 
operating conditions consisted of the following: carrier gas, N2, 13 mL 
min"^; H2 flow, 50 mL min'^; air flow, 500 mL min"^; injector tempera- 
ture, 105°C; detector temperature, 105°C; integrator, HP 3390A. Peak 



3-6 

area and retention times for DMSe were compared with reference standards 
which had been made by diluting 99.5% DMSe. 

After analyzing the headspace, the cap was removed and the flask 
was flushed with air for 30 min. Analysis for DMSe was carried out at 
24-h intervals up to 120 hours. All treatments were performed in 
replicates of five. The methylated gas was unequivocally identified 
as DMSe by gas chromatography-mass spectrometry (GC-MS). 

Gas Chromatography-Mass Spectrometry 

The gas chromatograph (Hewlett-Packard 5890) was equipped with a 
db-5 capillary column (J&W Scientific, Folsom, CA) 30 m in length with 
a 0.25 mm internal diameter. The mass spectrometer was a Hewlett- 
Packard 5970 MSD. The operating conditions were as follows: injection 
temperature, 220°C; column temperature, 50°C rising to 180°C after 2 min 
at a rate of 10°C min"^; mass spectrometry scan, 40 to 270 scans s~^; 
threshold, 600; electron impact, 70 eV; and ionizing source temperature, 
250°C. A 5-mL sample was taken directly from the headspace using a 
gas-tight syringe and injected directly. 

Factors Affecting Biomethylation of Selenium 

The soil (25 g) was saturated with MUB (50 mL) corresponding to the 
following pH values: pH 5, 6, 7, 8, and 9. Tests showed that with a 
soil:MUB ratio of 1:2, the pH of the soil-buffer mixture did not deviate 
more than +0.1 pH unit. 



3-7 



Moisture 

The soil (25 g) was treated with the following moisture regimes: 
air-dry, 12 mL (-33 kPa, 2.5 pF), 25 mL (1:1 paste) and 75 mL (1:3, 
soil:water) of deionized water. In the experiments to follow, a 
moisture content of -33 kPa (field capacity) was maintained. 

Temperature 

The soil (25 g) was moistened with 12 mL of deionized water and 
incubated at the following temperatures: 5, 15, 20, 25, 30 and 35°C. 
To one set of flasks, D-galacturonic acid (2 g C kg"^ soil) was added 
and incubated at 25°C. The effect of temperature on the biomethylation 
reaction can be expressed in terms of a temperature coefficient (Qiq) 
which is the factor by which the rate constant is increased by raising 
the temperature 10°C. 

Biomethylation at °T 



10 Biomethylation at °T-10°C 



Organo-Selenium Substrates 

The sediment was treated with the following organic Se compounds 
(200 mg C kg"'^ soil) serving as substrates for methyl ati on: seleno-DL- 
cystine, seleno-DL-ethionine, 6-selenoguanosine, 6-selenoinosine, 
seleno-DL-methionine, 6-selenopurine and selenourea. The respective 
controls consisted of DL-cystine, DL-ethionine, guanosine, inosine, 
DL-methionine, purine and urea. 



3-8 



L-Methiom'ne 

The influence of L-methionine on volatilization of Se was tested 
by applying 0, 0.1, 1, 10, 100 and 1000 mg L-methionine kg"^ soil. 

Carbohydrates 

Among the C sources assessed for stimulation of Se methyl ation, 
the following compounds were added at a rate of 2 g C kg"^ soil: 
glucose, fructose, fucose, sucrose, lactose, maltose, and rhamnose. 
Other compounds tested (2 g C kg"^ soil) included: cellobiose, cellu- 
lose, chitin and starch. Further studies were conducted to determine 
the optimum concentration of D-galacturonic acid to promote Se methyla- 
tion. The concentrations applied were 0, 0.09, 0.4, 0.9, 1.8, 3.6 
and 9.0 g C kg'^ soil. 

Proteins 

Three proteins were evaluated for enhanced DMSe production includ- 
ing casein, egg albumin, and gluten. The optimum concentration was 
determined by applying 0, 0.05, 0.1, 0.5, 1.0 and 2.0 g C kg"^ soil. 
In addition, a protein hydrolysate, peptone (2 g C kg"^ soil) was 
evaluated as an amendment for stimulating Se volatilization. 



3-9 



RESULTS 

Gas chromatography-mass spectrometry was used for the unequivocal 
identification of DMSe released from soil. The identity of DMSe was 
determined on the basis of its molecular weight and characteristic 
fragmentation pattern in relation to a reference standard. Figure 3-2 
shows the mass spectrum of DMSe with the appearance of the major ions 
being 110 (molecular ion) and 95 (base ion). No attempts were made to 
quantify DMDSe released. 



Factors Affecting Biomethylation of Selenium 
£H 

The optimum pH for methyl ati on of Se in the presence of MUB was 
pH 8.0 (Fig. 3-3). MUB was selected because of its buffering capacity 
over a wide pH range. For comparison, DMSe production by Alternaria 
alternata isolated from evaporation pond water was reported to have an 
optimum pH of 6.5 (Thompson-Eagle et al . , 1989). In this study, the 
methylating activity of Se at pH 8.0 was approximately 1.34X and 1.16X 
greater than the extreme pH values of 5.0 and 9.0, respectively. 



Moisture 

Figure 3-4 illustrates the biomethylation rates for DMSe at various 
moisture regimes. Very little DMSe evolved under air-dried conditions. 



lOOr 



CHjSeCHj 



3-10 



80 



95 



> 

UJ 

H 



60 



LJ 
> 

- 40 

< 
llJ 

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92 



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83 



06 

\ 




40 



60 



■iilil.i ■illllllll , ,iiIIIIIl 



80 

MASS 



100 



120 



Fig. 3-2. Mass spectrum of dimethyl selenide (DMSe). 



3-n 



ro 
I 



40 



C7> 

J 30 

Q 
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50 



100 



50 



TIME (h) 



Fig. 3-3. Influence of soil pH on DMSe production. 



3-12 



20-h INCUBATION 



•o 80 




50 100 

TIME (h) 



D AIR DRY 

▲ MOIST 

■ |:| PASTE 

A 1=3 SOIL- 
WATER 

L__ 

150 



Fig. 3-4. Influence of moisture content on DMSe production from 
soil. 



3-13 



The optimum moisture content appears to be at field capacity (-33 kPa) 
(approximately 70% of the water holding capacity) with lower emission 
rates occurring under waterlogged conditions (1:1 paste and 1:3 soil: 
water). These rates were expected since obligate aerobic fungi are 
thought to be the predominant Se nethylating organisms among the soil 
microflora. However, it should be noted that considerable DMSe evolved 
from the submerged soil. Chau et al. (1976) also found substantial 
amounts of DMSe being produced by sediment samples saturated with water 
(3:1) in the laboratory. Cooke and Bruland (1987) reported the presence 
of methylated Se compounds (DMSe, DMDSe and DMSe^-R) in diverse natural 
aquatic systems and suggested that biomethylation of Se is a widespread 
process. 

Temperature 

The rate of Se methylation increased with increasing temperature 
(5-35°C) with the optimum for DMSe production from soil being 35°C 
(Fig. 3-5). The methylation activity was approximately 17.8-fold 
greater at 35°C than at 5°C. The average Q,^, was calculated to be 2.60. 
That is, for every 10°C rise in temperature, the rate of biomethylation 
of Se increased 2.6-fold. In another set of flasks, soil was treated 
with D-galacturonic acid (2 g C kg~^ soil) and incubated at 25°C. With 
the addition of C, the rate of the biomethylation reaction was increased 
2.63-fold over the unamended soil when incubated at the same temperature. 
Adding C was as effective in promoting biomethylation of Se as raising 
the temperature 10°C. 



3-14 



JT 300 
ro 




TIME (h) 



Fig. 3-5. Influence of temperature on DMSe production from soil 



3-15 



Organo-Selem'um Substrates 

Among the organo-Se compounds added to the seleniferous soil, 
selenomethionine enhanced the methylation reaction 6.18-fold over 
the pooled average of the other organo-Se substrates tested (Fig. 
3-6). Doran and Alexander (1977a) reported similar findings with 
substantial amounts of DMSe being produced from selenomethionine added 
to soil. The addition of selenoethionine, selenoguanosine, selenopurine 
and selenourea slightly inhibited biomethylation of Se in comparison 
to the control. This experiment also revealed that methionine and 
ethionine stimulated DMSe production 3.6-fold over the unamended 
control, while cystine, guanosine, purine, inosine and urea had little 
effect. The stimulation of DMSe production by selenomethionine might 
have been caused by the cleavage of the methionine constituent. It 
has been speculated that methionine or its metabolic metabolites 
(e.g., S-adenosylmethionine [SAM]) could serve as a methyl donor 
in transferring a methyl group directly to the Se atom during the 
microbial methylation reaction (Doran, 1982). Doran and Alexander 
(1977b) reported that SAM enhanced production of DMSe from Se(IV) and 
elemental Se when catalyzed by cell -free extracts of Corynebacterium sp. 



3-16 



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3-17 



L-Methionine 

Since L-methionine (L-MET) applied to the seleniferous soil 
enhanced the microbial methylation of Se, it was of interest to deter- 
mine the optimum concentration for DMSe production. Figure 3-7 shows 
that there was little difference between the gaseous Se evolved by the 
unamended control, 0.1 and 1.0 mg L-MET kg~^ soil. The optimum L-MET 
concentration appears to be 100 mg kg"^ soil. Production of DMSe was 
even evident at 1000 mg L-MET kg"^ soil. To obtain a better under- 
standing of the mechanism involved in the formation of DMSe, further 
work is needed to determine if SAM added to soil also stimulates DMSe 
production. 

Carbohydrates 

Among the carbon sources tested, glucose was most effective in 
enhancing DMSe production (2.69-fold) (Fig. 3-8). Other carbohydrates 
which stimulated DMSe production included: sucrose (2.27-fold), maltose 
(2.15-fold), fructose (1.69-fold), lactose (1.15-fold), fucose (1.10- 
fold), and rhamnose (1.05-fold). Polysaccharides were less effective in 
stimulating Se methylation. Only cellobiose (1.76-fold) and chitin 
(1.21-fold) promoted DMSe production (Fig. 3-9). Starch and cellulose 
showed no enhancement under short term incubation (120-h). Previous 
studies have shown that plant residues which are comprised of many of 



3-18 



200 



to 



20-h INCUBATION 



E 

Q 

UJ 

(f) 

< 

LU 

_! 

LU 100 

CC 

0) 
CO 



fO 



E 

Q 
UJ 
CO 
< 



CO 




CONTROL 0.1 1.0 10 100 1000 
L-METHIONINE (mg kg"' soil) 



L-METHIONINE 
(mg kg~' soil) 




D CONTROL 


▲ 0.1 


■ 


1.0 


A 


10 


• 


100 


O 


1000 

1 



50 



TIME (h) 



Fig. 3-7. Influence of L-methionine on DMSe production from soil. 



3-19 



200 



ro 
I 



E 
o 

LU 

< 
LU 

_l 
LU 
(T 

(D 
if) 



00 



rT 200 



20-h INCUBATION 




D CONTROL 

♦ GLUCOSE 
■ SUCROSE 
O MALTOSE 

• FRUCTOSE 
O LACTOSE 
A FUCOSE 

A RHAMNOSE 

I 



50 



100 
TIME (h) 



150 



Fig. 3-8. Influence of carbohydrates on DMSe production from soil. 



3-20 



^ 1.2 
'5 



<D 

CO 

J 0-8 

Q 
UJ 

O 
> 

LU 

^ 0.4 



120-h INCUBATION 




D CONTROL 
▲ CELLOBIOSE 
• CHITIN 
A STARCH 
■ CELLULOSE 



50 100 

TIME (h) 



150 



Fig. 3-9. Influence of polysaccharides on DMSe production from 
soil . 



3-21 



these constituents also stimulate the evolution of DMSe from soils 
(Abu-Erreish et al . , 1968; Doran and Alexander, 1977a; Karlson and 
Frankenberger, 1988b). 

D-Galacturonic Acid 

Karlson and Frankenberger (1988b) reported high volatilization 
rates of ^^Se (IV and VI) upon incorporation of pectin to soil. 
Pectin is a polysaccharide present in cell walls of plant tissues func- 
tioning as intercellular material. This polysaccharide is a methylated 
polymer of D-galacturonic acid with small amounts of galactose and ara- 
binose. Since pectin was so effective in stimulating DMSe production, 
this experiment was conducted to determine if D-galacturonic acid would 
also be active in promoting this microbial reaction. Figure 3-10 indi- 
cates that there was little difference in biomethylation of Se between 
D-galacturonic acid applied at 0.09, 0.4 and 0.9 mg C g" ^ soil and the 
unamended control. However, when galacturonic acid was added at 1.8 
and 3.6 g C kg~^ soil, biomethylation of Se was enhanced 1.97- and 
3.70-fold, respectively. The highest amount of D-galacturonic acid 
applied (9 g C kg"^ soil) was less effective. 

Proteins 

Among the proteins tested as soil amendments, casein and egg 
albumin dramatically enhanced DMSe production (Fig. 3-11). No other 



3-22 




D CONTROL 


^ ♦ 0.09 


■ 0.4 


O0.9 


) • 1.8 


1 O 3.6 


▲ 9.0 

1 



150 



TIME (h) 



Fig. 3-10. Influence of D-galacturonic acid on DMSe production from 
soil. 




3-23 



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3-24 



treatment tested in this study was as effective. The optimum protein 
treatment was 0.1 mg C as albumin kg"^ soil. This treatment enhanced 
gaseous Se emission 19.3-fold over the unamended control. Other 
application rates of albumin (0.05 to 2.0 g C kg" ^ soil) were also 
effective in stimulating DMSe production. Casein had a strong stimu- 
latory effect (16.7-fold increase) when applied at 2.0 g C kg" ^ soil, 
while other loading rates of casein were considerably less effective. 
Gluten applied to the seleniferous soil enhanced DMSe production from 
1.32-fold (1.0 g C kg"^ soil) to 2.60-fold (0.5 g C kg" ^ soil). The 
highest application rate of gluten (2.0 g C kg"^ soil) inhibited 
biomethylation of Se. Peptone (2 g C kg"^ soil) also enhanced DMSe 
production (1.42-fold) in comparison with the unamended control. 



DISCUSSION 

This study indicates that there are various amendments that can 
be added to seleniferous soil to promote the volatilization of Se. The 
optimum pH was found to be pH 8 which is within the same range as the 
Kesterson soils. The optimum moisture content appears to be at field 
capacity. The soil should be well aerated to facilitate gaseous dif- 
fusion of DMSe. Warm temperatures enhance DMSe production indicating 
that the summer months will accelerate this microbial transformation. 
Organo-Se (e.g., selenomethionine) as well as inorganic Se compounds 
can be used as substrates for Se volatilization. Specific amino acids 



3-25 



and carbohydrates were found to stimulate DMSe production. Among all 
the compounds tested, proteins (e.g., casein, albumin and gluten) 
enhance biomethylation of Se more than any other treatment. Further 
work is needed to test the effect of protein sources on Se volatili- 
zation in the field. 



CHAPTER 4 

TOXICITY AND FATE OF ALKYLSELENIDES 
IN THE ENVIRONMENT 

Toxicity 

Professor 0. G. Raabe and co-workers at the University of 
California, Davis conducted a study on the toxicity of inhaled 
dimethyl selenide (DMSe) in the adult rat. Their report is enclosed 
in Appendix B. The acute toxicity of inhaled DMSe was studied with 
a total of 85 adult rats exposed to four concentration levels for 
one hour. The exposure apparatus consisted of a syringe-pump device 
for delivery of DMSe at a steady state rate connected to the nose of 
the rodent. The levels of exposure were 0, 1607, 4499 and 8034 ppm 
which are unusually high levels to bracket an LDrj, dose exposure 
relationship. Upon exposure, the animals were observed for a one week 
period for clinical abnormalities. Not a single animal was killed by 
the gaseous DMSe. All the animals appeared normal during the 7-day 
observation period. 

The exposed and control rats were then sacrificed and their major 
tissues and organs were examined. There was a slight increase in the 
lung weight after one day of exposure. There was also slight injury to 
the spleen with increased spleen protein and RNA at the highest con- 
centration (8034 ppm) but normal recovery was noted later. This 
effect appeared to be more of an irritation rather than an injury. 



4-2 



Histological sections of the lung, liver, spleen, thymus, lumph nodes, 
pancreas and adrenal gland were examined and appeared normal. Protein, 
DNA and RNA content of the liver and lungs were measured to quantify the 
minor inflammation response. Changes in the liver and lungs appeared to 
be minor and after 7 days, the organs were completely recovered. The 
selenium (Se) content in the lungs and serum were slightly elevated 
at day one post exposure, but it appears that the half-live of DMSe 
is very short and the compound is eliminated mainly via the lung. 

The data indicate that inhaled DMSe vapor is nontoxic to the rat. 
However, DMSe does have a stenchy odor and at high concentrations can 
be offensive. This study is in agreement with other investigations in 
which DMSe is reported to be 500 to 700X less toxic than Se(IV) and 
Se(VI) (LDgQ of DMSe = 1600-2200 mg Se kg"^ rat) (Wilber, 1980; Ganther 
et al . , 1966; McConnell and Portman, 1952). Upon uptake of Se, the 
major metabolites are considered DMSe (exhaled from the lungs) and 
trimethylselenonium (excreted in the urine). The conversion of Se(IV) to 
DMSe has also been characterized through in vitro studies of liver homo- 
genates and liver fractions (Hsieh and Ganther, 1975). Methylation of 
selenium is considered to be a detoxification mechanism for micro- 
organisms, animals and most likely man. This is consistent with the 
contention that DMSe appears to be innocuous in nature. 

Fate of Gaseous Selenium 

On a global scale, trace element cycles are being studied through 
models considering steady-state (stationary) and nonsteady-state 



4-3 



(transient) cycles with emphasis on sinks and sources of elements. 
Selenium is considered as a atmophile volatile element. More 
information is needed on the cyclic nature of Se within the biosphere, 
atmosphere, hydrosphere and lithosphere. 

Selenium can be emitted into the atmosphere in substantial 
quantities in the vapor phase through coal-fired electric power 
plants. Other high temperature sources include fossil fuel burning, 
industrial activities such as smelting, volcanism, and burning of 
vegetation. Burning of vegetation includes forest fires and wood for 
fuel. The Se to C ratio of vegetation is roughly 2 x 10"''. If 2500 x 
10^^ g of carbon are released annually to the atmosphere through burning, 
approximately 5 x 10® g of Se would be released. 

Some natural low temperature processes releasing Se to the 
atmosphere include physical, and biologically mediated volatilization 
processes such as aerosol generation at the sea surface and biomethyla- 
tion from soil microorganisms and plants. 

MacKenzie et al . (1979) developed a global model for the geo- 
chemical cycle of Se with physically defined spheres (land, ocean, 
atmosphere and sediments). The transport path, a directional property 
of the system, is highly dependent on the physicochemical character- 
istics of Se including solubility and vapor pressure. Transport modes 
involve stream and groundwater flow, rainfall, wind, erosion, gas 
exchange, sedimentation and uplift. 

The importance of the anthropogenic flux was evaluated by de- 
termining the interference factor (total anthropogenic emissions/total 



4-4 

natural emission). For Se, the anthropogenic flux is considerably 
greater than the natural flux. Total anthropogenic emissions from land 
(120 X 10® g/yr) is approximately 4-fold greater than the natural flux 
(23 X 10® g/yr). 

Although the concentration of volatile Se compounds in the atmos- 
phere has not been measured, low temperature volatilization appears 
to be a widespread process. Terrestrial biogenic fluxes of Se to the 
atmosphere result from microbial activity in soils and leaf-mediated 
volatilization from plants. It is very difficult to estimate the 
biogenic contribution because i) the Se concentration in soils, 
plants and sediments are highly variable, ii) Se emissions have only 
been measured in the laboratory, and iii) the biological emission rates 
are highly dependent on speciation and the oxidation state of Se 
available for uptake. 

Recently CHjM Hill (1988) reported the potential air quality 
impacts from enhanced volatilization of Se and estimated the deposition 
rate of volatilized Se in the surroundings of Kesterson Reservoir. The 
Se volatilization rates were considered in an air quality dispersion 
model (WYNDvalley) developed by Harrison (1987) to simulate Se emission 
rates to the atmosphere under three sets of wind conditions. The actual 
wind speed and direction on location were recorded from March 1, 1986 to 
February 28, 1987. This model allowed variation in boundary conditions 
with emission intensities and wind diffusivities that affected dis- 
persion of the atmospheric Se. The assumed wind conditions were 
0.66 m sec"\ 2.29 m sec"^ and in the worst case scenario, completely 



4-5 



stagnant. Field tests indicate that a Se volatilization rate of 250 ug 
m~ h~ represents an emission rate which would be promising for reme- 
diation of Kesterson Reservoir. Isopleths were constructed for each of 
the simulated wind conditions. The highest brief exposure of Se under 
stagnant conditions was 2408 ng m"^ (less than 1 h duration) with the 
highest 24-h average computed at 837 ng m"^. With wind velocities 
as measured in December, 1986, the highest brief episode (1 h) of Se 
was 711 ng m~^ with a 24-h average Se concentration of 246 ng m~^. 

The State of California and EPA do not have established ambient air 
quality standards for Se to compare the acceptable inhalation exposure 
levels. Acceptable ambient air Se concentrations for states 
(Connecticut, Massachusetts, Nevada and Virginia) that do have standards 
range from 2700 ng m~^ over 24 hours to 5000 ng m"^ over 8 hours. An 
acceptable intake level documented by the EPA in guidance for superfund 
sites is considered to be 3500 ng m"^ which is significantly higher than 
that expected at Kesterson Reservoir. 

The deposition flux of gaseous Se was calculated assuming a resi- 
dence lifetime of 9.6 days in air for DMSe (MacKenzie et al . , 1979), 
a well -mixed air layer of 50 m in height, a short range distance from 
Kesterson Reservoir at <10 km and light winds with a deposition velocity 
of 5 m d~^. Using the WYNDvalley model with wind velocities of December 
7-22, 1986, a 24-h average air Se concentration would be about 250 ng m" ^ 
at Kesterson Reservoir and approximately 50 ng m at a distance of 
10 km. At a deposition velocity of 5 m d"^, the deposition flux would 



4-6 



be 4.5 g ha" yr" at Kesterson and 0.9 g ha"^ yr" ^ at a 10 km distance. 
The deposition flux of Se at 100 km was calculated at 0.009 g ha" ^ yr" ^ 
The impact of volatilized Se on the surrounding lands near Kesterson 
Reservoir is expected to be minimal. At the highest annual deposition 
flux (4.5 g Se ha"M tnixed in the upper 10 cm of soil, the soil Se 
content would be increased by about 0.005 ppm. 



5-1 



CHAPTER 5 

PHYSICOCHEMICAL PROPERTIES OF DIMETHYLSELENIDE 
AND DIMETHYLDISELENIDE 



Introduction 

Volatilization is a significant pathway for Se loss from soil and 
water (Craig, 1986). It is defined as the loss of chemicals from a 
surface in the vapor phase, that is, vaporization followed by dif- 
fusion into the atmosphere (Spencer et al . , 1984). Volatilization 
rates of chemicals from surface deposits are directly proportional to 
their relative vapor pressures (Spencer et al . , 1984). Therefore, 
vapor pressure is a key parameter controlling the behavior of 
methylated Se in the environment, along with water solubility, 
soil adsorption, stability, wind speed and air turbulence. Vapor 
pressures often increase 3- to 4-fold for each 10°C rise in 
temperature. For dimethyl selenide (DMSe) and dimethyldiselenide 
(DMDSe) the vapor pressure has not been determined to date. 

Environmental partitioning of methylated Se between soil, water 
and air depends on several factors, including Se solubility in water 
(Davis et al . , 1988). The solubility of methylated Se species has 
yet to be determined. Confusion exists in the literature about this 
important physicochemical property. Characterizations range from 



5-2 



"insoluble" in the case of DMSe (Strem, 1985), over "relatively inso- 
luble" for methylated Se compounds (Davis et al . , 1988), to "soluble" 
for methylated Se species (Cooke and Bruland, 1987). There is a need 
to quantitate the solubility of DMSe. 

Recently, microbial volatilization of Se has been considered as an 
alternative means to detoxify Se-contaminated sediments (State Water 
Resources Control Board, 1988). Application of certain soil amend- 
ments was found to strongly stimulate soil Se volatilization (Karlson 
and Frankenberger, 1988b, see Chapter 3). The major volatile product 
was identified as DMSe, along with small amounts of DMDSe (Karlson and 
Frankenberger, 1988a). The dissipation of soil Se by microbial volati- 
lization is expected to depend on the rate of microbial production of 
methylselenides, their solubility in water, their adsorption to soil 
surfaces, and their diffusion into air. The latter is dependent on 
the vapor pressure of the Se compounds and its change with temperature. 
To predict volatile Se emissions, the physicochemical parameters for 
the major Se species involved need to be determined. This study was 
undertaken to determine the vapor pressure of DMSe and DMDSe, and the 
solubility of DMSe. Further studies are in progress to determine the 
solubility of DMDSe. 



5-3 



MATERIALS AND METHODS 

Vapor Pressure 

Analytical grade DMSe and DMDSe was obtained from Stren Chenicals 
(Newburyport, MA). The vapor pressure of DMSe and DMDSe was 
determined by the isoteni scope method (Prutton and Maron, 1949). The 
experimental apparatus is illustrated in Fig. 5-1. Approximately 5 mL 
of DM{D)Se were placed in the reservoir, and a small amount in the 
U-tube attached to it. Under a slight vacuum, the sample was heated 
to vigorous boiling to expel all air between the reservoir and the U- 
tube. Then the temperature in the water bath was lowered to the 
desired level by adding ice. The thermometer bulb was placed close to 
the liquid DM(D)Se in the reservoir. Using a hose clamp on the air 
intake line, the pressure of the system was adjusted until equilibration 
between reservoir and mercury (Hg) column was achieved, i.e., the 
DM(D)Se levels in the U-tube were exactly equal. Vapor pressure was 
calculated as the difference between the height of the Hg column at 
equilibrium and that of an Hg barometer column. 

Solubility 

The solubility of DMSe in water was determined in a closed system 
consisting of a silanized 125-mL screw-top Erlenmeyer glass flask and 
a Mininert valve-septum (Dynatech, Baton Rouge, LA). The exact 
interior volume of the system was 141.235 mL. The flask was filled 



5-4 [ 




I 
la 



a> 



■o 



a> 






1- 
o 

Q. 

> 



T3 
O) 

3 • 

0) 

v> in 

Z3 a 
■»-> 2 
(O a 
t_ 
« -a 

Q. c 

Q. la 
<a 

•— CO 

•M o 

c 

O) <«- 

E o 
t- in 
a. o 



I 

LT) 



CT 



q: 



5-5 



with 100.000 mL of purified (Millipore, Milford, MA) water and closed 
with the valve-septum. Using a syringe, DMSe was added to the system. 
Its quantity was determined by weight increase. Proper seal of the 
septum was confirmed by repeated weighing after 24 h. The system was 
maintained at 25°C in a water bath. Equilibration of DMSe between the 
undissolved, the dissolved and the gas phase was facilitated by shaking. 
After 20 min, equilibration was assumed and vapor density was determined 
in the headspace. This was repeated 15 min later to confirm equilibra- 
tion. Following this procedure, additional quantities of DMSe were 
added to the system, until the headspace vapor density had reached a 
maximum. 

The vapor density of DMSe in the headspace was determined by 
taking a 1-mL aliquot in a gas-tight syringe, diluting it with air in 
a silanized 125-mL glass flask (holding a few glass beads and 
stoppered with a Mininert valve-septum), and injecting a 0.25 mL 
aliquot of the dilution directly into an HP gas chromatograph (Model 
5890; Hewlett-Packard, Avondale, PA). The instrument parameters were 
as follows: 3-m packed stainless steel column with liquid phase, 10% 
Carbowax 1000, and solid support, Chrom W-AW, mesh 60/80; flame 
ionization detector; column temperature, 58*0 rising to 80°C after 2 
minutes at 70°C min' ; injector/detector temperature, 105°C; carrier 
gas (He), 10 mL min"-^; N2, 30 mL min" ; H^, 40 mL min" ; air flow, 370 
mL min" . The signal was recorded with a Hewlett-Packard model 3393A 
integrator. Peak area was linear from to 10 ng Se injected. 



5-6 



Standards were prepared by evaporating a weighed amount of DMSe in a 
large silanized glass container and making serial dilutions. The 
retention time for DMSe was 3.5 min. 

The solubility of DMSe in water at 25°C was calculated from the 
intercept between the sloped and the horizontal segment of a plot 
fitted to the headspace vapor density data. The total amount of DMSe 
in the headspace was subtracted from the inferred quantity of DMSe 
added to the system at the intercept. 



RESULTS 

Vapor Pressure 

The vapor pressure of DM(D)Se as dependent on temperature is 
illustrated in Figs. 5-2 and 5-3. The simple regression equation for 
DMSe is: 

log P = -1.208 + 0.0191 T [1] 



and for DMDSe, 



log P = -10.324 + 0.0433 T [2] 



where T is the temperature in K and P is the vapor pressure in Pa. The 

correlation coefficients were r = 0.999 (P < 0.001) and r = 0.993 

(P < 0.001), respectively. The vapor pressure for DMSe and DMDSe at 
25°C was calculated at 31.46 and 0.38 kPa, respectively. 



5-7 



(0 

a. 



o 




4.0 



270 



280 



290 



300 



310 



320 



T {°K} 



Fig. 5-2. Vapor pressure of DMSe versus temperature. 



5-8 






o 




280 



290 



300 



310 



320 



T {°K} 



Fig. 5-3. Vapor pressure of DMDSe versus temperature. 



5-9 



Solubility 

For determination of solubility, the simple regression equations 
for Fig. 5-4 were derived as 

C^ = 0.29154 + 1333.8 W; r = 0.998 (p < 0.001) [3] 
C^ = 1948.1; r = 0.99 (p < 0.1) [4] 

where W is the quantity of DMSe added to the system, and C-, and Co are 
the headspace methyl selenium concentrations in the sloped and in the 
horizontal segment of the graph, respectively. Assuming a constant 
headspace volume of 41.235 mL, and with a water volume of 100.000 mL, 
the solubility of DMSe was calculated to be 0.0138 g mL"^ H^O at 25°C. 

Heat of Vaporization 

From one form of the Clausius-Clapeyron equation, the slope (m) of 
the graph of log P versus 1/T is related to the heat of vaporization 
by the equation: 

aH^ = -2.303 R(m) [5] 

where aH is the heat of vaporization in J mol' and the gas constant 
R is in J K"-'- mol"-^. For DMSe and DMDSe the heats of vaporization 
were calculated to be 31.90 kJ mol"-*- and 74.92 kJ mol"-'-, respectively 
(Fig. 5-5). 



5-10 



2500 



2000 






o 
u 

(0 

a. 
o 



0) 
C/) 



1500 



1000 



500 




2.0 



DMSe added {g} 



Fig. 5-4. Vapor density of DMSe in the headspace (41.235 mL) over 
Hj (100.000 mL) versus total DMSe added to the system. 



5-n 



4- 



3- 



DMDSe 



y = 15.709 -3.9128X r=.993 



— I — 

3.2 



— I — 
3.3 



y = 10.093 -1.6659X r=.999 



DMSe 



3.1 



3.4 



3.5 



3.6 



1000/T {1/°K} 



Fig. 5-5. The relationship between vapor pressure of DMSe and DMDSe 
and the reciprocal of temperature. 



5-12 



DISCUSSION 

Combining the results from the vapor pressure determinations and 
the solubility measurements allows calculation of Henry's Law constant. 
It is defined by: 

P = kX [6] 

where P is the headspace vapor pressure at a defined temperature, and 
X is the concentration in the underlying solution. Using the maximum 
concentration of DMSe in water at 25°C (Fig. 5-4), and the calculated 
vapor pressure for 25°C, we arrive at 

k = 20.9 kPa g H2O mol'-^ 

for DMSe. 

Applying the same approach to the calculation of the apparent 
vapor pressure 

w RT 

P, = [7] 

a V M 

where w/V is the measured vapor density and M is the molecular weight 
of DMSe, we are able to confirm the results of the isoteniscope 
measurements. For DMSe, the P, was 44.28 kPa. This estimate is 

a 

within 41% of the direct measurement, which is considered satisfactory. 

With 31.46 kPa at 25°C, the vapor pressure of DMSe is approximately 
5 times that of alcohol and 1/2 that of ether. The vapor pressure of 
DMDSe (0.38 kPa at 25°C) is approximately 1/10 of that of water. 



5-13 



Because of the. exponential relationship between temperature and 
vapor pressure, DM(D)Se is expected to become overproportionally 
volatile with increasing temperature. Raising the temperature from 10°C 
to 25°C approximately doubles the vapor pressure of DMSe, while rais- 
ing the temperature from 25°C to 40°C doubles it again, i.e., produces 
a vapor pressure 4 times as high as at 10°C. This agrees with earlier 
findings that Se field emission rates are highly dependent on soil and 
air temperature and increase dramatically with the onset of the warm 
season (Frankenberger and Karlson, 1988a). 

Some of the literature suggests a low solubility of DMSe in water. 
However, water was found to be an effective eluant for DMSe absorbed to 
activated charcoal (Lewis et al . , 1966; Karlson and Frankenberger, 
1988a). The data presented here establish a high solubility of DMSe 
in H2O and confirm those earlier findings. With regards to -the goal of 
rapid soil Se removal through volatilization, a high solubility of DMSe 
in water means that microbially produced methyl selenium may dissolve in 
soil water films, which would increase its probability of being adsorbed 
and scavenged by other microorganisms, and decrease its rate of dissipa- 
tion into the atmosphere. This obstacle could possibly be overcome by 
raising the soil temperature, thereby increasing the vapor pressure 
and by promoting wetting and drying cycles. 



6-1 



CHAPTER 6 
DESCRIPTION OF FIELD EXPERIMENT 

Field experiments at Kesterson Reservoir commenced on 28 July 1987. 
Areas measuring 100 x 100 ft and 150 x 150 ft, respectively, in Ponds 4 
and 11 were disked until the upper 4 to 6 inches of soil were loosened. 
The area was then rototilled. Test plots 12 x 12 ft with 8 ft borders 
were staked out in both ponds (see Figs. 6-1 and 6-2). This experiment 
consisted of a randomized complete block design. 

Date of Applications 

Amendments were applied according to the following schedule: 

29-30 July 1987 Initial application of straw, cattle manure and citrus 

pulp (see pages 6-5 to 6-8 for application rates). 

1 September 1987 Repeat application of manure and citrus pulp. NH^NOo 

(5 lbs N) applied to subplot 66 and ZnSOl, (1 lb Zn) 
added to subplots 63 and 64. Straw was not applied 
to the straw subplots (2,5,9,52, 55 and 59), but 
20 lbs of straw were added to subplots 16, 18, 19, 
20, 23, 24, 25, 26, 51, 53, 60, 63, and 64 (to 
increase porosity). Forty lbs of cattail straw 
were applied to subplot 66. 



6-2 



HAZERS 
I COMPOUND 



GUN CLUB ROAD 




59' 



^^ 





62 




63' 









65' 





.0. S *^^ 



N 



^ 



\g\B 



ic3 



ya\ \^ V26\ 



SAN LUIS 

DRAIN EXPERIMENT 



Fig. 6-1. Layout of field plots in Pond 4, Kesterson Reservoir. 



6-3 




® © /^ r-^ 

P^ ^ W g7 nr^ 
^ S P7 ^ 



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> 

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cse. 



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6-4 



5 October 1987 



1-2 December 1987 



5-6 April 1988 



15 June 1988 



20 July 1988 



28 July 1988 



19 September 1988 



Repeat of initial application (no fertilizers). 
One-half the rate of straw was added to straw 
subplots, and no straw was added to the other 
treatments. Manure was no longer added to the high- 
rate manure subplots 24 and 26. 

All treatments (no fertilizers) were applied except 
straw was added only to subplots 51, 53, 60, 63 and 
64 (20 lbs). 

All treatments (no fertilizers) were applied, straw 
was added to subplots 2, 5, 9, 52, 55, and 59 (20 lbs). 
Added 5 lbs of gluten/subplot to 2, 5, 9, 52, 55 and 59 
(formerly straw plots). 

All treatments (no fertilizers) were applied except 
straw. Subplots 2, 5, 9, 14, 17, 21, 27, 28, and 29 
received no amendments. Added 5 lbs of gluten to sub- 
plots 52, 55, 59. No cattail was applied to subplot 66 
this time. 

Added 5 lbs of casein to subplots 2, 5, and 9 and 
10 lbs to subplot 65 (formerly molasses). 
Applied 5 lbs of casein to subplots 2, 5, and 9. 
Applied all treatments to San Luis Drain experiment. 



6-5 



POND 4 MAIN EXPERIMENTS 



Subplot number Treatment 

51 Manure 

52 Straw (C/N = 10) 

53 Manure 

54 Citrus pulp 

55 Straw (C/N = 10) 

56 Moist 

57 Moist 

58 Citrus pulp 

59 Straw (C/N = 10) 

60 Manure 

61 Citrus pulp 

62 Moist 



Treatment details (initial application): 

Manure : cattle manure from Harris feedlot, 10% H2O, 650 lb (wet wt)/ 

subplot applied (equiv. to 89 t/ac). 

Straw (C/N = 10) : barley straw, dry, chopped, 66.6 lb/subplot (equiv. 

to 10 t/ac) plus (NH,^)2S0i, applied. 
Citrus pulp : orange pulp from Sunkist, Tustin, CA, non-processed; 

80% H2O, crude protein >_ 1.6%, 1000 lb (wet wt)/subplot 

applied (equiv. to 30 t/ac). 

Protein : gluten or casein (Sigma, St. Louis, MO) applied at a 

rate of 5 lb/subplot (equiv. to 0.75 t/ac). 

POND 4 SIDE EXPERIMENTS 

Subplot number Treatment 

63 Citrus pulp + N + Zn 

64 Citrus pulp + N + Zn 

65 Molasses 

66 Cattail straw 



6-6 

Treatment details (initial application): 

63,64 orange pulp (80% HjO), 1000 lb (wet wt)/subplot 

(equiv. to 30 t/ac) + N [(NHi,).2S04] + ZnSO^ (Zn, 
1 g kg~^ orange pulp; N, 5 g kg~^ orange pulp) 

65 740 lb molasses/subplot, NOT rototilled in originally 

(too sticky); rototilling started 25 August 1987 

66 40 lb cattail straw, not chopped, originally no N 

addition 



POND 11 MAIN EXPERIMENTS 



Subplot number Treatment 

1 Manure 

2 Straw (C/N = 10) 

3 Manure 

4 Citrus pulp 

5 Straw (C/N = 10) 

6 Moist 

7 Moist 

8 Citrus pulp 

9 Straw (C/N = 10) 

10 Manure 

11 Citrus pulp 

12 Moist 



Treatment details (initial application): 

Manure : cattle manure from Harris feedlot, 10% H2O, 650 lb (wet wt)/ 
subplot applied (equiv. to 89 t/ac). 

Straw (C/N = 10) : barley straw, dry, chopped, 66.6 lb/subplot plus 

(NH^)2S0l, applied 



6-7 



Citrus pulp : orange pulp from Sunkist, Tustin, CA, non-processed; 

80% H2O, crude protein >_1.6%, 1000 lb (wet wt)/subplot 
applied (equiv. to 30 t/ac). 

Protein : gluten or casein (Sigma, St. Louis, MO) applied at a 

rate of 5 lb/subplot (equiv. to 0.75 t/ac). 

POND 11 SIDE EXPERIMENTS 



Subplot number 


Treatment 




13 


Citrus pulp + Zn + 


N 


14 . 


Straw (C/N = «, no 


N added) 


15 


Citrus pulp + N 




16 


Citrus pulp 300 




17 


Straw (C/N = 20) 




18 


Manure 450 




19 


Manure 300 




20 


Citrus pulp 450 




21 


Straw (C/N = 5) 




22 


Citrus pulp + Zn 




23 


Citrus pulp 650 




24 


Manure 1000 




25 


Citrus pulp 1500 




26 


Manure 1500 




27 


Straw (C/N = «., no 


N added) 


28 


Straw (C/N = 5) 




29 


Straw (C/N = 20) 




30 


Moist 




Treatment details 


(initial application): 





13,15,22 1000 lb (wet wt)/subplot orange pulp (80% HjO) (equiv. 

to 30 t/ac) + N [(NH^)2S0^] and/or ZnSO^ (Zn, 1 g/kg 
orange pulp; N, 5 g/kg orange pulp) 



6-8 



14,17,21,27,28,29 barley straw, 66.6 lb/subplot (equiv. to 10 t/ac) + N 

addition to provide C/N ratio of «., 5 and 20 

16.20.23.25 orange pulp, 80% HjO; apply 300, 450, 650 and 1500 

lb (wet wt)/subplot (equiv. to 9, 14, 20, 45 t/ac) as 
indicated. 

18.19.24.26 feedlot cattle manure, 10% H2O (estimated), apply 

300, 450, 650, and 1500 lb (wet wt)/subplot (equiv. to 
41, 62, 137, and 206 t/ac) 



ROTOTILLING 

All plots were rototilled to 6" within 24 hours after application 
of the amendments. In addition, all plots were rototilled every other 
week during the winter if weather permitted, and once a week in the summer. 

IRRIGATION 



Irrigation started on 30 July 1987. The irrigation system is 
comprised of 1/2" PVC tubing with outlets consisting of microjets. The 
irri-gation time varies from 3 to 10 min with daily applications except 
during the winter months. Water quality: Kesterson shallow well water, 
used through 5 August 1987 (EC^ = 11.3 dS m"M; after 5 August 1987, 
well water from the Los Bafios yard (0.64 dS m"i). 



6-9 



Irrigation was conducted daily until 22 October 1987. After that 
time, rainfall interrupted the irrigation schedule until May 1988. 
Water application rates were reviewed and altered periodically. Water 
quantities were adjusted after visual examination of the top soil with 
the goal to keep the soil moist but minimize leaching of the soluble Se 
below the 4-inch depth. 



SAN LUIS DRAIN EXPERIMENT 

On September 19, 1988, a pilot study was initiated on the San Luis 
Drain sediment at Kesterson Reservoir. This study involves monitoring 
the volatilization rates of Se and removal of residual Se in soil sub- 
jected to selected treatments with time. Figure 6-3 indicates the site 
where the sediment was collected. The sediment was excavated out of the 
drain, air-dried, and mixed. It was then placed in layers approximately 
6" deep into 3x3' boxes (50 kg/box). The location of this experiment is 
at Pond 4 adjacent to our existing plots (Fig. 6-1). Treatments con- 
sisted of a comparison between citrus pulp, proteins and a check. The 
sediments are frequently watered and aerated. Being a homogeneous 
mixture, soil sampling is representative of the inventory removed, not 
having to deal with spatial variability. Loss of Se through aqueous 
flux (leaching) is excluded since the boxes are closed at the bottom. 
There are three replicates per treatment. 



6-10 



is 



O 



UJ -I ^ 

I — I 

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in 



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C 
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0) 
0) 

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6-11 

Treatments 

Moist only 

Gluten (82 g/box) 

Casein (82 g/box) 

Albumin (82 g/box) 

Citrus pulp (10.09 kg/box) 

Citrus + cobalt (10.09 kg citrus + 10.9 g CoCl g'SHjO/box) 

Straw + N (650 g barley straw [chopped] + 74.3 g NH^NOs/box) 

Cottonseed meal (500 g/box) 



SOIL AND GAS SAMPLING 

A) Profile Sampling 

Profile samples at 0-6 inch, 6-12 inch, 12-18 inch, and 18-24 inch 
increments were taken from the center of plots 2, 4, 6, 10, 24, 25, 
51-64 on 7/29/87 and on 11/25/87. On 1/19/88, samples were taken 
along the border of plots 59, 63, 65, and 66 to 24". Profile samples 
were also taken in plots 51-66 on 7/24/88. 

B) Soil Surface Sampling 

All plots were sampled in a five-point pattern at the to 6 inch 
depth on: 7/29/87, 9/11/87, 10/5/87, 11/9-10/87, 12/1/87, 1/14-19/88, 
3/1/88, 4/1/88, 5/1/88, 6/7/88, 7/11/88, 8/3/88, and 9/6/88. 

C) Gaseous Se Sampling 

All plots were sampled for gaseous Se in the center of each plot 
on the following dates: 

Pond 4 : 10/23/87, 10/26-27/87, 11/10/87, 12/16-17/87, 1/13/88, 2/3/88, 
2/5/88, 2/23/88, 3/3/88, 3/17/88, 3/24-25/88, 4/4/88, 4/12/88, 4/20/88, 



6-12 



4/27/88, 5/10/88, 5/17/88, 5/24/88, 6/3/88, 6/17/88, 7/6/88, 7/13/88, 
7/18/88, 7/19/88, 7/25/88, 8/1/88, 8/8/88, 8/12/88, 8/23/88, 8/30/88, 
9/1/88, 9/6/88, 9/15/88, 9/19/88, 9/21/88, 9/29/88. 

Pond 11 : 10/15-17/87, 11/9/87, 12/16-17/87, 1/14-19/88, 1/21-22/88, 
2/3-4/88, 2/22-23/88, 3/3/88, 3/24-25/88, 4/12-14/88, 4/22/88, 4/28/88, 
5/9/88, 5/18/88, 5/23/88, 6/8/88, 6/23/88, 7/7/88, 8/2/88, 8/11/88, 
8/29/88, 9/9/88, 9/14/88, 9/20/88, 9/23/88, 9/28/88. 

San Luis Drain Sediment: 9/22/88, 9/26/88, 9/29/88. 



7-1 



CHAPTER 7 
MONITORING VOLATILE SELENIUM EMISSION IN THE FIELD 

Apparatus 

The apparatus used for in-field measurements of alkylselenide 
production was the same as designed by 0. Wares, LBL (Fig. 7-1). 
Inverted galvanized steel boxes 22"x22"x4" with a brass tubing connector 
at the top center were used as flux chambers. Additional equipment 
required for this operation consisted of a compressor vacuum pump 
(Fisher, Tustin, CA), 250 mL gas washing bottles (40-60 \f\ porosity) 
(Fisher, Tustin, CA) , 6-place manifold, 1/4" I.D. vinyl tubing, and 
surgical tubing. Reagents used for the scrubbing solution were hydrogen 
peroxide (H2O2) (30%) and 0.05 _N sodium hydroxide (NaOH). The purpose of 
the peroxide was to oxidize the' volatile Se into the Se(VI) species. 

The flux chambers were placed in the center of each subplot to be 
sampled and pushed into the soil approximately 2". The vacuum pump 
was connected to an electrical supply near Pond 4 or a generator in 
Pond 11. The manifold was then connected to the pump with vinyl tubing. 
A trap was inserted between the manifold and pump to prevent the scrub- 
bing solution from being drawn into the pump in case the gas washing 
bottle was tipped or blown over by the wind. From the manifold, 6-20 ft 
sections of vinyl tubing were connected to the sampling boxes. The 
scrubbing solution consisted of 80 mL 0.05 N NaOH (premeasured) plus 



7-2 




7-3 



20 mL of H2O2 (30%) (final = 6%) which was kept cold in an ice chest 
until used. Because vinyl tubing binds to glass and makes it difficult 
to attach and remove from the washing bottle, a small piece of surgical 
tubing was placed on the end of the vinyl tubing to alleviate this 
problem. After H2O2 was added and all the tubing was connected, the 
pump was started. The flow rate of the manifold was adjusted at the port 
of each chamber with a flow gauge to 2 L min"-^. The flow rate was moni- 
tored in the field throughout the day during sampling. The duration of 
the measurements was on an hourly rate with the starting and finishing 
times being recorded. In most cases, measurements were made at mid-day. 
Air and soil temperatures were monitored at the onset and end of sampling 
and recorded in field logs. Likewise, the temperature and relative 
humidity inside the flux chambers was recorded. 

Soil temperature was taken from random plots. A thermometer was 
inserted into the soil bermed up against the chamber approximately 2" 
below the surface. The air temperature was taken in the shade of the 
water tank. At the end of the sampling period the pump was turned off 
and temperatures were again recorded. The washing bottle was opened and 
the alkali-peroxide solution was poured directly into a 125-mL polyethy- 
lene bottle and placed into an ice chest packed with blue ice. The 
washing bottles were then rinsed twice with deionized water and filled 
with 80 mL of 0.05 N NaOH to be used for the next sampling. 

The alkali -peroxide sample was boiled to drive off the residual H2O2. 
A large hot plate with the capacity to hold 12 - 250 mL beakers was 
used. Each sample was boiled for 15 min, allowed to cool, brought up 
to volume (100 mL) and poured into 125-mL polyethylene bottles. 



7-4 



Background Levels 

Background samples were taken on non-rototil led, nontreated sites 
adjacent to the plots. These readings ranged from 0.82 to 10.08 (avg. = 
3.53) ug Se m"^ h"^ at Pond 4 and non-detectable to 3.33 (avg. = 1.04) 
yg Se m"^ h"^ at Pond 11. 

Shipping of Samples 

All samples were refrigerated (4°C) overnight before shipping. 
They were placed in an ice chest with several blue ice packs and either 
shipped next-day delivery by bus, or driven directly to Riverside by 
the field manager. The samples were then immediately placed into a 
cold room at 4°C and analyzed within 2 weeks. The chain-of -custody 
records were signed upon receipt of samples. 



Analysis 

Solutions were analyzed for total Se at UCR by taking a 25-mL 
aliquot into a 50-mL graduated test tube and adding 25 mL concentrated 
HCl (final concentration = 6 N HCl). The samples were then boiled for 
1 h, allowed to cool and brought to volume with deionized H2O. The Se 
content was analyzed by AAS/hydride generation on a Varian Spectra-10 ABQ 
single beam AA spectrophotometer. Results are reported as volatile 
emission rates expressed in ug Se m-2 h~i. 



7-5 
Method Development 

Boil ing 

Preliminary tests were performed to determine the time required to 
boil samples for reduction with HCl . Fig. 7-2 illustrates that 15 min of 
boiling is sufficient when compared with 1 to 2 h. However, unboiled 
samples resulted in low recovery, ranging from 67-70% to that of boiled 
samples. 

In another preliminary study, the Se content was determined in 
samples that were boiled, and then allowed to cool for 24 h before being 
analyzed again. Among 10 samples, the average Se content after 24 h from 
boiling was only 37% of those boiled samples. The range of recovery 
was 8 to 63%. It is highly recommended that the samples be analyzed by 
AAS immediately after boiling. 

Recovery 

Alkaline-H202 traps were operated as in the field, except detached 
from the sampling chamber. In place of the sampling box, a 3-inch length 
of V2-inch (dia.) latex tubing with an air-intake valve was connected to 
the intake tubing of the trap. The length of the intake tubing was 
varied between and 2.5 feet. Air-flow rates were adjusted to 0.5, 
1.0, 1.5, 2.0, and 3.0 L min-i. Dimethylselenide (DMSe) standards 
were injected through the latex tubing using a gas-tight syringe. DMSe 
gas standards were prepared by weighing small quantities of liquid DMSe 
into a 10-L glass bottle stoppered with a Mininert septum and allowing 



CO 

">. 

S) 

3 

>^ 

9 
U) 

UJ 



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a 
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lu-r 



12 



10 



PLOT 51 







Unboiled 



15 min 



1 hr 



2hr 



BOILING 



s 

ea 

N 



LU 



< 

mi 



> 




Unboiled 



15 mm 



1 hr 



2hr 



BOILING 



Fig. 7-2. Effect of time of duration in boiling for reduction of Se. 



7-7 



ft to evaporate. Equivalent DMSe amounts of 2 to 150 ug Se (representing 
6.5 to 500 ug m"2 h"i volatilization in the field, assuming 100% recovery 
and 1-h sampling) were applied in duplicates and at the different flow 
rates. Traps were analyzed according to the previously described 
procedure. Recovery was independent of tubing length and of Se quantity. 
It was only slightly, but insignificantly, dependent on the flow rate. 
The highest recovery was achieved at 2.0 L min"^ and was 85.6 +_ 4.4% 
(Fig. 7-3). 



7-8 



One^SUndTd D«v^.U„ Error B.r^ for X Recov.ry of DHSe in Alk.lia« Pero«.de Trno. 




1.5 
Flow Rate IL/min) 



Fig. 7-3. 



Percent recovery of dimethyl selenide in alkaline-peroxide 



8-1 
CHAPTER 8 

EMISSION RATES OF VOLATILE 
SELENIUM IN THE FIELD 

Emanation of volatile selenium (Se) was monitored in the field at 
Ponds 4 and 11 and in excavated San Luis Drain sediments. A complete 
description of the measuring techniques used for gas sampling including 
equipment (Chapter 7), frequency (Chapter 6), and QA/QC protocol 
(Appendix C) is described elsewhere. The data are expressed in the form 
of histograms for each sampling date. The error bars depict the standard 
error (t[^_^) of the data. In addition to measuring the gaseous Se 
released, the air and soil temperatures were recorded. 

Pond 4 
Temperature 

Figure 8-1 indicates the soil temperature minima and maxima at 
Pond 4 for each sampling interval. The soil temperatures ranged from 
4°C (2/3/88) to 50°C (7/18/88). The month of July had the highest 
temperatures with a decline observed in August and September, 1988. 

It is evident that a seasonal variation exists in microbial volati- 
lization of Se. Overall the greatest emission of gaseous Se was released 
in July, 1988, which correlates with the high soil temperatures. Less 
volatile Se was produced in the fall and winter months (Sept.-Mar.) . 
This is in agreement with the study of Callister and Winfrey (1986) 
monitoring the methylation of mercury in river sediments. There also 



8-2 



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T — I — I — I — , — \ — ^ — I — I — I — \ — r 

^.r--coooaooocooooo<»ooooa5ooaoaoooooaoooooooco°ooooo 
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Fig. 8-1. Soil temperatures recorded at Pond 4, Kesterson 
Reservoir from October, 1987 to September, 1988. 



8-3 



appears to be a high temporal variability in the gaseous Se data. This 
is most likely a result of variation in the daily temperature, moisture 
content, availability of organic matter, and Se content. 

Irrigation and Tillage 

Irrigation with tillage alone (subplots 56, 57 and 62) caused Se 
volatilization rates as high as 167 yg m~^ h"^ (Fig. 8-2). The average 
volatile Se emission rate during the year with this treatment was 27.3 ng 
m"^ h"^ being considerably higher (7.7-fold) than the average background 
levels for Pond 4 (3.53 ug m"^ h"M (Table 8-1). Moisture is definitely 
a limiting factor for volatilization of Se. The months with the greatest 
activity in terms of Se volatilization were June, July and August, 1988. 

Cattle Manure 



Compared with the moist-only treatment, the application of cattle 
manure to Pond 4 was 34% less effective in promoting microbial vola- 
tilization of Se. The peak of activity was observed from 6/24/88 to 
8/30/88 (Fig. 8-3). The emission flux of volatile Se during the 
year ranged from 0.17 to 116 uQ ^'^ ^'^ with an average rate of 18.0 
yg m"^ h"^. Perhaps the added N with the manure was responsible for 
this lower flux since it is now known that amendments with low C:N 
ratios inhibit volatilization of Se (Karlson and Frankenberger, 1988b), 



8-4 



160 



140 - 



120 - 



E 
& 

(A 



100 - 



SUBPLOTS 
56 57 62 



so- 



so - 



40 - 



T 







C\JC\l'-'-'-'-OCMO'-C\JO'-C\JCM 

— — > o d c ^ j3 "-^ --^ ■-: - ■ -^ ^' --■ 
OOzQQ-^Li.u.225 



o r~- TT en r^ 
T- ■.- c\j o •- 



c\j 



co" fo oo" (sT lo" ■^" oo" cj fo' o' '^ lo o* r: S* 

OT-.r-.p-(MOO.-CMC0 >-— (MCM 



Q. a a a 
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(TJ (Tj fT3 



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-J -3 



§33333 §'§'§'§'§'§•§■§■§■§■ 



Sampiing Date 



Fig. 8-2. Influence of moisture on Se volatilization from Pond 4, 
Kesterson Reservoir. 



8-5 



Table 8-1. Average background emission rates of gaseous selenium 
at Kesterson Reservoir. 



Se volatilized (^g m"^ h"-^) 
Month Pond 4 Pond 11 

ND* 

0.24 

0.51 

0.94 

0.45 

0.53 

1.28 

0.91 

0.83 

1.33 

1.39 

1.24 

Average 3.53 0.80 

*ND, not detectable 



October 1987 


2.86 


November 1987 


2.04 


December 1987 


1.04 


January 1988 


3.44 


February 1988 


2.14 


March 1988 


2.80 


April 1988 


5.32 


May 1988 


4.31 


June 1988 


5.14 


July 1988 


4.64 


August 1988 


4.61 


September 1988 


4.06 



8-6 



E 

& 
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no 



100 - 



90 



80 - 



70- 



60 - 



50 - 



40 - 



30 - 



SUBPLOTS 
51 53 60 




h.h>r^r^r^coeoao®vvaoaoaocoA(BQO®QOooaoaoaoaoaoaoaoaoaoao®ooaoaoao 
aoaoco<svcoaocoo°o®aoaooooo<oaoaoaoaoaoaococoaoaoooaoaoaoao°ocoaoooao 



C\JC\J'<-'-'~'-OCJOr-C\J 



^ =j a; o o rf ^ 

i\ f\ ^ m m *^^ ^S 






c\j 



to' n oo" o> irT »-' oo" cj crT o" '^ i" <" *- o> 
0'.---'.-ogoO'>-c\j<r) '-■^cjcm 



C C C — — — -=-= 0J0)0)0)0) 



a. a Q. Q. a. 



002QQ-sULU.222<<<<222-}-^-^-5-9-?-s-s^^^^^cowcowco 



Sampling Date 



Fig. 8-3. Influence of cattle manure on Se volatilization from 
Pond 4, <esterson Reservoir. 



8-7 



Barley Straw Plus N 

The application of barley straw plus N [(NH^)2S0^] was also ineffec- 
tive in promoting this microbial transformation. The peak of volatile 
Se was recorded on 4/27/88 with as much as 131 yg m"^ h"^ being released 
(Fig. 8-4). The average emission flux of volatile Se with this treat- 
ment during the year was 23.7 pg m"^ h"^ which is approximately 13% less 
than the moist treatment alone. 



Molasses 

The application of molasses to subplot 65 is comparable to the moist 
only subplots in terms of volatile Se released (Fig. 8-5). Molasses was 
applied as a rich C amendment since it contains approximately 50% sucrose 
and 11% amino acids. Our previous laboratory studies have shown that car- 
bohydrates stimulate microbial volatilization of Se (Chapter 3; Karlson 
and Frankenberger, 1988b). Upon the initial application of this amend- 
ment the emission rate of volatile Se was 1.90-fold greater than the moist 
only treatment, but quickly returned to the native rates. The peak of 
activity was noted from 6/17/88 to 7/19/88. The range of volatile Se 
released during the year was from 1 to 98 yg m"^ h"^ (avg. = 24 yg m"^ h"^), 



Cattail Straw Plus N 

Subplot 66 received several applications of cattail ( Typha latifolia ) 

straw, a plant indigenous to the area, and was monitored for volatile Se 

(See Fig. 8-6). On 9/1/87, NH4NO3 was applied to narrow the C:N ratio 



8-8 



120 - 



100 - 



E 

■ 

(0 

o 




CO 






o u 
O O 



o 


r^ 


CO 




CO 

o 


CO 
CM 


> 
o 


o 

Q 




d 

-5 


U. 


n 

0) 

u. 



en r~ 
o •- 



(T) nj 03 
Z 2 S 



00 

00 


oo 
oo 


oo 
oo 


00 
00 


o 


C\j" 


o" 


CM 


a. 
< 


Q. 

< 


a. 
< 





oo 

CO 



00 

oo 



oo 

00 



o 1^ ■<»• 
^ ^ c\j 

>>>>>> 
ns ns (TS 

2 s s 



00 

00 



CO 
o 



Sampling Date 



Fig. 8-4. Influence of barley straw on Se volatilization from 
Pond 4, Kesterson Reservoir. 



8-9 



100 



E 
tn 

0) 







aocoaooo°o°Ocoao°ocoaoaoaocoaoooaoooaoaoaocoooaoaoao 



CJCNJ^'-'-'-OCVJO — <No 



cv,- o" r-" <=> "^ ;:j 55 C:: 



CM 



CO n 00 a> in 

O >- T- >- Py| 



O O g <D (D 

O O z Q Q 



nj (2) (9 (^ <Q 



2. O. Q. Q. a. 



n} n3 nl 
2 S S 



= = §3=333 



-3-3-3 



Sampling Date 



Fig. 8-5. Influence of molasses on Se volatilization from 
Pond 4, Kesterson Reservoir. 



8-10 



E 
en 
(f) 




^.fs.^^^-r«•aoaocofloaocoaoaoaocoQOcoaoeoooooao 
aooooooococoooaooocoaoaoaoooooooaocoooaoooco 



GOGOaOQDcOGOOOOOaO^®^^^ 



to" r~r o" f^ ^ CO en CO co" r^ ^" «■" c\j" o" fvT o" h»" ■*" crT r-" 'r co" ci oo" o>" in ■?-" oo" cm" co o 'o uS oT »- oi" 
e\jCMi-'-'-'-ocMOt-c\joT-c5c\j'~'~^C)'-<^0'-'-'-<voO'.-cMcn "■"■ 



-- ■.- CNJ C\J 



Sampling Date 



Fig. 8-6. Influence of cattail straw on Se volatilization from 
Pond 4, Kesterson Reservoir. 



8-11 



and enhance decomposition of the cattail. The low emission rate of 
volatile Se was comparable to the cattle manure treatment. The peak of 
activity was noted from 7/13/88 to 9/21/88. The range of volatile Se 
released during the year was 0.2 to 39 ug m"^ h"^ with an average of 
13.4 ug m"^ h"^. 

Citrus Pulp 

The application of citrus pulp (orange peel) (subplots 54, 58 and 
61) dramatically increased the volatile Se released (Fig. 8-7). Citrus 
pulp was applied because of its high pectin content (30-35%). Karl son 
and Frankenberger (1988b) reported that pectin is very active in 
promoting microbial volatilization of Se. Seasonal activity was noted 
with the peak of volatile Se occurring in the month of August, 1988. 
The emission flux of volatile Se was as high as 702 yg m~^ h" \ averaging 
61.2 pg m~ h"^. The application of citrus promoted the volatilization 
rate 2.2-fold over the moist-only plots. 

Citrus Pulp + Zn + N 

When citrus pulp was supplemented with zinc (Zn) and N fertilizers 
the volatilization rates were enhanced 5.6-fold over the moist-only 
treatment and 43.5-fold over the background controls (Fig. 8-8). The 
emission flux was as high as 808 ug m"^ h"^ with an average of 153.7 uQ 
m"^ h~^ during the year. Subplot 63 was always the most active in 
production of alkylselenides (avg. = 201.2 ug ^'^ h"^). The addition of 
certain elements such as cobalt (Co), nickel (Ni) and Zn have been 
reported to accelerate volatilization of Se (Karlson and Frankenberger, 



8-12 



(A 

O 

cn 



600 



550 



500 



450- 



400 - 



350 - 



300 - 



250 - 



200 - 



150- 



100 - 



SUBPLOTS 
54 58 61 




p'^^-r^r^'^oooooofloooflocoooeoooooflooooooooocooooooooooooooooooooooooooooo 



■ <o in O)" I-" o>" 



to r^ o" 1^ <o CO CO CO CO ^. V Tf cvT o" tvT o r*^ •^ co" rC V to" co" oo' o>" in i-^ oo evi co o -• — 

r^ r^ ^ <T* m V "^ ^r 



c = c ■= -= — — 



a Q. a. a. Q. 



002:QQ-5ii-u-222<<<<225-5-3T-'-5-'-'^<<<<<a3coa5coco 



Fig. 8-7. 



Sampling Date 

Influence of citrus pulp on Se volatilization from 
Pond 4, Kesterson Reservoir. 



8-13 



0) 



800 - 



700 - 



600 - 



500 - 



400 - 



300 - 



200- 



100- 




rs.rv.r~r«.r-.oooooo«o«oooooaoooas2««oooooeooooooooo«oo 
oooooo«oooooooooooooooooaooooooo®oo*®*®®®*®oo 



00000000^0^®®® 
0000®®®®®®® 



co" r-" o" f^" to" CO m m m < V ,t' ou o" t--" o" i^" ;?" 2 i^" 5i S «^" ®" <^' )P, ZZ 2 '^" J?[ 2 '^ !i2 2 "j^ SI 



c c 

-3 -3 



"= "= 0)0 0)0)0) 



a. a a a a 



3 3 3 3 
< < < < 



_ IS O 0) 3) 3) 
<; CO CO CO C/3 CO 



Sampling Date 



Fig. 8-8. 



Influence of 
from Pond 4, 



citrus + Zn + N on Se 
Kesterson Reservoir. 



volatilization 



8-14 



1988b). We believe that these elements added at moderate to high 
concentrations will selectively enrich for metal and metalloid resistant 
microorganisms which can take advantage of the added C and methylate the 
Se. The addition of Co is thought to play a direct role as a cofactor 
in the methyl ation reaction. 

Proteins 

Two proteins (gluten and casein) were tested as amendments in the 
field to promote volatilization of Se. Gluten is a wheat protein which 
is intermixed with the starchy endosperm of the grain and is composed of 
approximately 80% protein and 7% lipids. After the application of gluten 
(6/15/88) to subplots 52, 55, and 59 (formerly straw + N), a burst of 
volatile Se was released (avg. = 90.3 ug m"^ h"^) (Fig. 8-9). High levels 
of volatile Se continued to be produced up to 7/25/88 and began to steadily 
decline thereafter. The peak of activity appeared to last approximately 
4 weeks. The emission flux of volatile Se from 6/17/88 to 9/29/88 ranged 
from 19 to 391 ^g m"^ h'^. 

Compared with gluten, casein was just as effective in promoting 
volatilization of Se. Casein is a mixture of phosphoproteins occurring 
in milk, cheese, beans and nuts. Like gluten, it contains all the com- 
mon amino acids. Immediately after the application of casein (7/28/88) 
the release of volatile Se was enhanced considerably (Fig. 8-10). High 
activity was maintained for approximately 3-4 weeks. The emission flux 
of volatile Se from 8/1/88 to 9/30/88 ranged from 4 to 311 ug m"^ h"^ 
with an average of 133.9 yg m"^ h"-^. 



8-15 



300 



250 - 



200 - 



(0 
CO 




150 - 



100- 



00 
CO 


00 

CO 


00 

00 


CO 

CO 


CO 
00 


00 
00 


CO 

CO 


00 

CO 


00 
CO 


00 
00 


CO 
CO 


CO 

00 


00 
00 


00 

00 


CO 
00 


00 
CO 


CO 
CO 


rC 


CM 


o 


m 


flo" 


o» 


C\J 





00" 



cvj" 


CD" 
CM 


0" 

CO 


CO 


in 


o> 


CM 


CM 


c 

-3 


C 
3 
-) 


3 
-3 


3 
-5 


■3 
-3 


"5 


"5 
-3 


3 
< 


d) 

3 
< 


3 
< 


d) 

3 
< 


d) 
3 
< 


Q. 
CO 


Q. 
03 
CO 


a. 

CO 


a. 

CO 


CO 



Sampling Date 



Fig. 8-9. Influence of gluten on Se volatilization from 
Pond 4, Kesterson Reservoir. 



3-16 



400 



350 - 



300 - 



250 - 



E 

■ 

O" 

« 
CO 




200 - 



150- 



100 - 



GO 
CO 


CO 

00 


00 

00 


OO 

oo 


OO 
CO 


00 

00 


00 

CO 


CO 
00 


00 
OO 


CO 
CO 


o 


oo' 

o 


e\j" 


CO 


CO 


(6 


lO" 


ai 


^ 


ai 

CM 


< 


< 


3 
< 


3 
< 


3 
< 


CO 


cL 


d. 

CO 


CO 


d. 

CO 



Sampling Date 



Fig. 8-10. Influence of casein on Se volatilization from 
Pond 4, Kesterson Reservoir. 



8-17 



Each of these proteins was subjected to amino acid analysis to 
determine any major differences in their composition. Casein contained 
twice as much aspartic acid and asparagine residues, three times more 
methionine and four to five times as much lysine than gluten (Table 8-2). 
Perhaps the greater quantity of methionine in casein than in gluten was 
responsible for the higher response in methylation of Se. We previously 
demonstrated that L-methionine greatly stimulates alkylselenide production 
in soil (Chapter 3). Purification and denaturation of these proteins may 
give more information on why they are so active in stimulating Se 
biomethylation. 



Pond 11 

The soil in Pond 11 has considerably less organic matter and Se con- 
tent (1.17 to 8.63 mg kg"^) than Pond 4 (10 to 209 mg kg"^). The primary 
vegetation is salt grass ( Distichlis spicata ). Treatments that were 
applied to Pond 4 were also applied to Pond 11 to determine which amend- 
ments were effective at both Se inventory levels. Pond 11 (median, 3.75 
mg Se kg~^) has approximately one-tenth the Se content as Pond 4 (median, 
39 mg Se kg~^). The emission flux of volatile Se in Pond 11 was expected 
to be an order of magnitude less. Subplots in Pond 11 were also used to 
determine the optimum loading rates of different amendments including 
straw:N ratios, cattle manure and citrus pulp. 



8-18 



Table 8-2. Amino acid composition of casein and 
gluten. 



Amino 
acid 



Casein 
mole wt 



Gluten 
mole wt % 



Asx 


1 

112 


Timol 100 g • 


52 


Glx 


183 




327 


Ser 


50 




47 


Gly 


23 




38 


His 


53 




39 


Arg 


28 




24 


Thr 


29 




19 


Ala 


29 




25 


Pro 


80 




103 


Tyr 


- 28 




16 


Val 


47 




29 


Met 


13 




7 


Cys 







19 


He 


31 




24 


Leu 


67 




51 


Phe 


25 




29 


Lys 


61 




11 



8-19 

Temperature 

Figure 8-11 illustrates the fluctuation of soil temperature at 
different sampling intervals. Temperatures ranged from 2.2°C (2/3/88) 
to 55°C (7/7/88). There was not a strong relationship between seasonal 
Se volatilization rates in Pond 11 and soil temperature as observed for 
Pond 4. This could be because of the limited supply of Se available 
for methyl ation. 

Irrigation and Tillage 

Merely adding water to Pond 11 soil promoted volatilization; 
however, no seasonal peak was observed during the year of sampling 
(Fig. 8-12). The emission flux of volatile Se ranged from 0.28 to 
11.40 (avg. = 2.23) ^g m"^ h"^. The application of water enhanced 
volatilization 2.8-fold over the average background level (0.80 ^g 
m"2 h"M. 

Cattle Manure 

Compared with the moist-only treatment, cattle manure (equiv. to 
89 t/ac) applied to subplots 3, 10 and 11 enhanced volatilization of Se 
1.37-fold (Fig. 8-13). This is in contrast to the Pond 4 data where 
manure was less effective in promoting volatilization. We believe that 
manure was an effective amendment in Pond 11 because of its darker color 
enhancing the heat absorption of the soil. These subplots evolved a 
considerable amount of alkylselenides during the winter months (11/9/87 
to 3/24/88). It is well known that darker soils have a higher heat gain 



8-20 



60 



50 



O 

o 



O 



(0 

a. 

E 

0) 

H 



O 
(f) 



40 



30 - 



20 - 



10 



Maxima 



Minima 




T 



T — I — I — I — I — I — I — I — I — I — I — I — I — r — I — I — I — I — I — I — I — I — r 

r^r**OOOOoOOOGOOOQOOOQOCOOOCOOOGOCOcOOOQOQOOOOOCOQOOO 
OOGOGOGOoOCOCOaOQOGOQOaO^^^^GOcOOOQOGO^^^^^ 



<ji (o Tt ■,- tn 

'- '- CM 



c\j CO 

C\i 



to CVJ CM OO 
^ .- CM CM 



i o> eo" m 



> 
o 



o 

a> 
Q 



C C -Q 13 ^ 
<Q 10 9> 3> Q> 
-3 -3 LI. LL LI. 



(8 <0 

2 s 



Q. a. Q. 
< < < 



-- CM 



(TJ (T3 (T5 



00 CO f^ 
CM 



irT cm" ai o> 

'- CM 



■«»■ o CO 00 

»- CM CM CM 



■ 6) 6> o- <^ ^ °- <^ 

^<<CO(Z)COCOCO 



Sampling Date 



Fig. 8-11. Soil temperatures recorded at Pond 11, Kesterson 
Reservoir from October, 1987 to September, 1988. 



8-21 



(A 
CO 

O) 

IS. 



12 



11 - 



10 - 



9 - 



8 - 



7- 



6 - 



5 - 



4- 



3 - 



2- 



1 - 



SUBPLOTS 
6 7 12 30 







-r 



>% 



r>. 


f^ 


00 


00 


on 


m 


m 


no 


(T) 


nn 


(T) 


nn 


on 


00 


00 


O) 


00 


00 


CO 


00 


00 


CO 


00 


00 


CO 


00 


CO 


CO 


00 


CO 


CO 


00 


CO 


00 


00 


00 


00 


CO 


CO 


CO 


a> 


<o' 


^" 


^ 


ci 


V 


cm" 

CVJ 


m 


<o 


C\J 


cJ 


CO 
CVJ 


oo" 

CM 


Ol 


co" 


en" 

CM 


CO 


CM 


r«." 


in" 


> 
o 

z 


Q 


c 

-5 


d 

(0 

-3 


0) 
LL. 


X) 

<s 

LL. 


u. 


(13 




(0 

2 


Q. 

< 


a 

< 


Q. 

< 


(TJ 


(T3 

2 


OJ 


c 


ci 

-5 


3 
-J 


3 

-5 



OOOOOOOOQOOOGOOO 

oosoocococococo 
cm" t^ ai "*" ■^" o" co" oo* 

•-CM -- CM CM CM 



Sampling Date 



Fig. 8-12. Influence of moisture on Se volatilization from 
Pond 11, Kesterson Reservoir. 



8-22 



(0 
0) 




00 


00 


oo 

00 


00 
00 


OO 
00 


00 

00 


OO 

00 


OO 
CO 


00 

00 


00 

00 


00 

OO 


00 

OO 


00 

00 


00 
OO 


00 
OO 


00 

00 


00 
OO 


00 
OO 


00 

00 


OO 
OO 


00 

00 


OO 
00 


00 

OO 


00 
00 


CO 
00 


00 
00 


00 
CO 


00 
00 


o> 


CO 


Tf 


^ 


CO 


■*" 


C\j' 


en" 


co' 


CM 


e\j" 


C\j" 
CNJ 


flo" 

CM 


O) 


oo" 


CM 


00 


co" 

CM 


p>-" 


in" 


cm" 


^ 


o>" 

CM 


CJ> 


■v' 


cT 

CM 


en" 

CVI 


oo" 

CM 


Z 


o 

ID 

Q 


c: 

-5 


c 

-3 


n 

(D 
Li. 


X) 
U. 


<a 


(8 

2 


2 


2 


a. 

< 


< 


a. 

< 


2 


(TJ 

2 


>< 

2 


c: 

3 

-i 


c 

3 
-5 


3 

-3 


3 

-3 


CJ> 

3 
< 


CJ) 

3 
< 


3 
< 


a 

CO 


Q. 
CO 


a. 

CO 


Q. 
CO 


<9 
CO 



Sampling Date 



Fig. 8-13. Influence of manure (equiv. to 89 t/ac) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



8-23 



by solar radiation. This indirect effect would be expected to have more 
of an impact on Pond 11 where the soil is light in color and relatively 
low in organic matter, whereas in Pond 4, manure would have less influ- 
ence since the soils are very rich in organic matter. An aerial view of 
Kesterson shows the manure-treated subplots in Pond 11 as quite distinct, 
being darker in color than the adjacent plots. The cattle manure was 
analyzed for its Se content to determine if Se was added along with the 
amendment. Selenium was not detected in the manure. The average 
emission flux of volatile Se with this treatment ranged from 0.48 to 
12.23 (avg. = 3.06) ^g m"^ h"^. 

When the loading rates of manure (equivalent to 41, 62, 137 and 206 
t [dry wt]/ac) were compared, volatilization of Se was slightly greater 
at the intermediate application rates (Figs. 8-14 to 8-17). The average 
emission rates of gaseous Se (ug m"^ h"-^) from 11/9/87 to 9/28/88 ranged 
as follows: i) 41 t/ac (ND [not detectable] to 7.09 [avg. = 1.71]), 
ii) 62 t/ac (ND to 12.61 [avg. = 3.71]), iii) 89 t/ac (0.48 to 10.49 
[avg. = 3.06]), iv) 137 t/ac (ND to 5.78 [avg. = 1.65]), and v) 206 
t/ac (ND to 7.96 [avg. = 2.42]). 

Barley Straw 

The application of barley straw without N fertilizer showed a slight 
response with greater volatile Se being released in the spring and 
summer months; however, the emission rates of volatile Se were very 
low (ND to 5.80, avg. = 1.65 ^g m'^ h"M (Fig- 8-18). Tests were made 
varying the C:N ratio by applying N fertilizer. In composting, it is 



8-2^ 



o 
CO 

O) 




CO 



^OOOOoOOOOOOOOOOOOO 

oooocoaoooaoaoaocoao 



o> to TT 1-" c) •^r 



T- ^ oj 



CM CO 
C\J 



> 
o 



o 

(S 

O 



0) 

u. 



u. 



to ■* 

r- C\J 

2 2 



OJ 



Q. 

< 



ts 

00 



C\J 
CM 



a. 
< 



ca 

CM 



00 00 
00 00 



(0 



00 CO 

■■- CM 

>. >. 

(0 « 



00 

oo 



00 



00 00 
oo 00 



CO 
00 



CO oo 

00 00 



c 

3 



r«. ut' CM T-" 



3 3 

< < 



CM 

3 ® 

< ^ 



00 
00 


00 
CO 


00 
00 


00 

00 




o" 

CM 


co" 

CM 


co" 

CM 


d. 

CO 


d. 

CO 


d. 

(0 
CO 


d. 

CO 



Sampling Date 



Fig. 8-14. Influence of manure (equiv. to 41 t/ac) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



8-25 



E 

CO 

o 




CO 



> 



00 


oo 

03 


CO 

CO 


00 

CO 


00 
CO 


00 
CO 


CO 
CO 


CO 
CO 


CO 

00 


CO 


'T 


w 


CO 


•^ 


C\j" 


erf 


co" 




Q 


c 

-3 


c 

-3 




n 

to 
u. 


u. 


(8 


2 


2 



00 CO ® ^ ® ® 

00 00 ^ ® '^ ® 



GO GO CO CO 00 GO ® 
CO 00 00 00 00 00 ® 



CNJ" CNj" oo' ^'^ ® CO 

^ CM CM '-CM 

ir ^ ^ ns (TJ OS ^ 

^^^2 2 2^ 



CO e»3 p>» 



c 

-3 



in c^ ^" oT <3> 

1- --CNJ 



CO 
00 



o 



00 
CO 



CM 



CO 
CO 



00 
CM 






Sampling Date 



Fig. 8-15. Influence of manure (equiv. to 62 t/ac) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



CO 

CO 




^ 


oo 


00 
CO 


OO 
oo 


00 

00 


00 
00 


oo 

00 


00 
00 


00 
00 


GO 
00 


oo 
oo 


00 
00 


00 
CO 


CO 
CO 


00 
00 


00 

00 


00 
CO 


OO 

CO 


00 

oo 


00 
00 


00 
00 


00 

00 


00 
00 


CO 
00 


CO 
CO 


CO 
00 


s 


00 

00 


O) 


CO 


■v" 


c\i 


CO 


■* 


cm" 

CVJ 


m 


to" 


CM 


cvj" 


CM 
C\( 


eo" 

C\J 


o» 


co" 


CO 

CM 


00 


CM 


r^" 


in 


cm" 


^ 


o>" 

CM 


at 


•«r 


o" 

CM 


co" 

CM 


oo" 

CM 


z 


(D 

o 


c 

-3 


cf 

(0 

-5 


<s 
u. 


S3 
(0 

u. 


J2 
li. 


(5 


2 


(5 

2 


< 


5. 

< 


< 


m 


>- 
nj 

2 


2 


c 

—i 


d 

3 
-5 


"5 

-5 


3 

-3 


3 
< 


3 
< 


3 
< 


a. 

® 

CO 


a. 

CO 


ca. 

<s 
in 


a. 

CO 


a. 

3) 
CO 



Sampling Date 



Fig. 8-16. Influence of manure (equiv. to 137 t/ac) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



8-27 



8.0- 



(0 




r*. 


fs. 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


00 


CO 


CO 


CO 


CO 


ou 


CO 


CO 


CO 


00 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


00 


CO 


CO 


O) 


CO 


•v' 


^ 


m 


•v" 


cm" 

CM 


m 


co" 


CM 


cm" 


cm" 

CM 


co" 

CM 


at 


co" 


co" 
CM 


> 
o 

Z 


o 

IS 

Q 


c 

(0 

-5 


c 

-3 


u. 


ri 

(D 

u. 


(D 
U. 


(8 

2 


(0 

2 


2 


a. 

< 


a. 

< 


CL 

< 


(0 


2 


f8 
2 



cocoaoaocococoaocoooco 

GOCOOOCOCOCOCOOOCO 



CO CO 
00 CO 



m CO n r^ 



CM 



ir> CM ^ O) 

^ ^ CM 



rr O CO CO 
■•- CVI CM CM 



-^^^<<<COCOCOCOCO 



Sampling Date 



Fig. 8-17. Influence of manure (equiv. to 206 t/ac) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



8-28 



(A 

CO 
O) 




00 


00 


00 
00 


oo 

00 


OS 
oo 


00 

oo 


00 
00 


OO 

oo 


00 
00 


OO 

oo 


a> 


CO 


TT 


^ 


en" 


V 


CM 


CO 


co" 


or 

CM 


z 


u 

<s 

Q 


c 

(0 

-3 


c 

(0 

-5 


u. 


li. 






2 


2 



cooooo^^^^^oooooooooooooooooooo 
oooooo^oooooooocooooooooooooooooooo 



CM CM 00 
1- CNJ C\J 



o» 00 cr> 00 CO i»- in CM ^" oT 

^ CM CM .p- »- CM 



o> 



^ O CO 00 
•^ CM CM CM 



i; t ^ nJ ns (0 
a. Q. a. -^ ■^ ■^ 
< < < 2 ^ ^ 



c c 

-3 -3 



: • 0> 0> C7) 

■33333 

-o -o < < < 



a. Q. a. a. Q. 

^ 35 ® ^ 05 
CO « CO CO CO 



Sampling Date 



Fig. 8-18. Influence of barley straw on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-29 



desirable to apply materials with a ratio of organic C to total N as 
narrow as possible to enhance decomposition. Organic C added in excess 
to that required for microbial tissue will generally be released as CO 2 
or complexed in the humic fraction of soil. Microbial tissues generally 
average 50% organic C and 5 to 10% total N (C:N ratio 10:1 to 5:1). 
There was very little difference in the volatile Se produced with C:N 
ratios of 5:1, 10:1 and 20:1 (Figs. 8-19 to 8-21). The emission rates 
of volatile Se (ug m"^ h"M from 11/9/87 to 9/28/88 at different C:N 
ratios were i) C:N = 5:1 (0.47 to 11.56 [avg. = 2.95]), ii) C:N = 10:1 
(0.38 to 6.46 [avg. = 1.81]), and iii) C:N = 20:1 (ND to 7.92 [avg. = 
2.23]) ug m'^ h"^. All the straw treatments with and without N had 
little effect in promoting Se volatilization. 

Citrus Pulp 

The application of citrus pulp (30 t/ac) to subplots 4, 8 and 
11 enhanced the Se volatilization rate 2.0-fold over the moist-only 
treatment. The emission flux of volatile Se ranged from 1.00 to 21.64 
(avg. = 4.47) ug m"^ h"^ (Fig. 8-22). There was more gaseous Se released 
in the summer compared with the winter months. There was little dif- 
ference between the various loading rates of citrus (Figs. 8-23 to 8-26). 
The emission rates of volatile Se (ug ni"^ h"M I'rom 11/9/87 to 9/28/88 
ranged from: i) 9 t/ac (ND to 19.15 [avg. = 3.4]), ii) 14 t/ac (ND to 
17.56 [avg. = 3.39]), iii) 20 t/ac (ND to 7.49 [avg. = 2.66]), iv) 30 
t/ac (1.00 to 17.66 [avg. = 4.47]), and v) 45 t/ac (ND to 13.98 [avg. = 
3.90]). In all cases with the application of citrus pulp, there was a 



8-30 







r<» 


1^ 


00 


00 


on 


en 


on 


or) 


no 


<T) 


<T» 


IT) 


m 


CO 


00 


00 


CO 


CO 


00 


00 


00 


00 


CO 


00 


00 


00 


CO 


CO 


00 


CO 


00 


00 


oo 


00 


00 


oo 


(3) 


CO 


■*" 


CM 


CO 


^" 


CNj" 


co" 


co" 


C\J 


<N 




oo" 


at 


oo" 


CO 
cv 


00 


m 

CNi 


> 
o 

z 


o 

IS 

Q 


c 

(0 

-3 


(8 

-5 


(0 

u. 


J3 
(0 


(D 


2 


2 


2 


OL 

< 


a 

< 


a. 

< 




2 


2 


-5 


c: 

-5 



oooocoooooooooooooo 
oooocooooooooocoooco 



r>- m c>j ^ o» 

'- »- CNJ 



■V o CO CO 

T- (Nl CVJ C\i 



• _: C3»C3)djS-9-S-S-g- 

— — ___ij)(Ba)a)<j) 



Sampling Date 



Fig. 8-19. Influence of barley straw + N (C/N = 5) on Se 

volatilization from Pond 11, <esterson Reservoir. 



3-31 



(A 
CO 




r^ 


r^ 


00 


00 


00 


00 


CO 


CO 


00 


CO 


00 


00 


00 


00 


oo 


CO 


00 


oo 


00 


00 


00 


00 


CO 


oo 


00 


03 


00 


00 


oo 


oo 


oo 


oo 


00 


00 


o> 


co" 


'»■" 


^ 


ci 


■<r 


CM 


m 


<o 




CNj" 


cm" 

CM 


oo" 

CM 


o> 


oo" 


in 
cu 


00 


z 


6 
Q 


c 

-5 


c 

(0 

-5 


X) 
(S 


u. 


X) 

a) 

u. 


2 


2 


at 


w 

Q. 

< 


o. 

< 


a. 

< 


(TJ 


2 


as 

2 


c: 

3 
-5 



Sampling Date 



Fig. 8-20. Influence of barley straw + N (C/N = 10) on Se 

volatilization from Pond 11, <esterson Reservoir. 



8-32 



CO 




I I I 
oocoooaoaococoaoaoooaoaoaocoaoaoaoco 



o> «o •^r ^" rt 

'- T- CM 



2: Q 



^ <^ en «■" 

•^ 2 S - CXi CM 



CM CM 



00" o> 00" n" 00 CO 

^ "- C\J CM 



= -9 



^ 
« 



(d ns cQ 
2 IS S 






00 

00 


oo 
00 


00 

00 


00 
oo 


00 
00 


OS 
00 


00 

00 


00 

00 


oo 

00 


CO 
00 


r«." 


m" 


c\i" 


^ 


<3>" 
CM 


o> 


•«»■" 


0" 

CNi 


en 

CM 


oo" 

CM 


"5 


"5 
— « 


< 


< 




d. 

CO 


Q. 
(B 
CO 


d 

CO 


d. 

CO 


d. 

CO 



Sampling Date 



Fig. 8-21. Influence of barley straw + N (C/N = 20) on Se 

volatilization from Pond 11, Kesterson Reservoir. 



8-33 



20- 



(A 




r>,r>-oooooooooooooocoa5ffl25i^^Q3aj 
ooooooooooooooeoaoooooQOoo»«'°°'"*' 



0» to TT •.- (TJ •^ 



— ^ c\i 



2 Q 



c 

(0 

-3 






u. 



c\j m 

CM 

■g I 



CM 

2 



CM CM 00 
^ CM CM 



o> 



00 CO <=o 

^ CM 



w i_ w (0 (TJ (0 i: 

Q. ca. Q- 5 5 5 ^ 

< < < ^ ^ ^ -3 



r^ in f^ •r- 



3 3 
-3 -5 



3 3 
< < 



(3>- 0» 
CM 

3 ® 



00 
00 


00 
CO 


00 
00 


00 

00 


■«f 


o" 

C\J 


co" 

CM 


oo" 

CM 


a. 

C/i 


cL 

CO 


d. 

CO 


d. 

CO 



Sampling Date 



Fig. 8-22. Influence of citrus pulp (30 t/ac) on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-34 



E 
« 

CO 




^!^SS^°oaoaoaocoaocoaoOOooaocooocoaoaoao<9oocoaoco 
(otsaocoaoooaoaoaoaococoao^oooooaoaoaoaoaoao'sso'sooao 



o> CO ■^ T- to 
'- »- c\j 



O' <3> OO" CO 00 



5^ « to" 'T c^* c^ <» 
c^ ^ ^ ^ c\j CVJ 



T- CM 

ca nJ (O 5 



crT r«." in" cvf ,-" ai o> tt" o' co oo" 

c . .d>cbd)9-S-2-9-9- 

D 3 3®®® ® ® 



-J-5^^<<<C0C0C0(»C0 



Sampling Date 



Fig. 8-23. Influence of citrus pulp (9 t/ac) on Se volatilization 
from Pond 11, Kesterson Reservoir. 



3-35 



(0 

CO 

o 

.=1 




rs.r^aoooooaoaocoooaoaoaoeo'naoaocoaoaocoaoaoaocoaoao 
ooaoaoaococoaoaoaoooaoaooo<Bcoaoaoaocoaooocoao<Baoco 



a> <D Tf ■,— ci 
»- »- c>j 



u 

a 



nj 03 a) 






CO ■* 



CM OJ CO 
^ <N CVI 



.- o> oo" (tT «o 



■^ CM 



u. u. u. 2 



OJ 






i; i; S <0 « <0 ^ 

a Q. □. 2 2 S 



< < < 



3 
-5 



CM 

c 

-5 



lO CM ^ 0> 
■.- ^ CM 



■<r o 

■^ CM 



. cj) d) d» 9- °- S- 

"5 3 3 3®,®® 
^ ^ ^ ^ CO CO C/3 



CO 00 

CO CO 

erf co' 

CM CM 

d. d 

CO CO 



Sampling Date 



Fig. 8-24. Influence of citrus pulp (14 t/ac) on Se volatilization 
from Pond 11, Kesterson Reservoir. 



•36 



or 

(A 
0) 




r>. 


t>^ 


03 


05 


03 


03 


03 


00 


00 


CO 


03 


00 


O) 


00 


OO 


CO 


03 


a 


03 


CO 


00 


CO 


00 


CO 


at 


CO 


'T 


^ 


CO 


■«r 


cm" 

C\J 


crT 


co' 


C\J 


CNi" 


C\i 


> 
o 

Z 


a 


C 
(8 

-5 


-5 




(9 
U. 


J3 


2 




(0 


w 
Q. 

< 


Q. 

< 



ooooooaoaocoooooooaooo®®co®co 

GOOOCOCOCOCOcOOOOOCOOO^OOOOCDCO 

oj" o> co" c^" *" fo' !*>•" m" cm" yS of o> tt" o en" co" 

C\j <-CM CM 1- ■.-CM "-CMCMCM 



^r (0 « (0 ^ 

5^2 2 2 ^ 



c_._. d)d)d>Q-S-9-S-^ 

-3^^<<<COCOWCOCO 



Sampling Date 



Fig. 8-25. Influence of citrus pulp (20 t/ac) on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-37 



15 



SUBPLOT 
25 



10- 



O" 
(0 



5 - 




00 



pN. 00 

00 00 



00 00 
CO 00 



00 00 

CO 00 



o> CO •^r 1- CO ^ 



'- T- cj 



> 
o 



u c 






CM 

(0 n 



CO 

CO 



(O 



CO 

00 

(5 

2 



00 00 

00 00 



C\J CM 
■«- CM 



Q. Q. 

< < 



00 CO 

00 00 

CM 

< ^ 



CO 



oooooooococooooooooooooooo 
oocooooocooooooooooocooooo 



n eo n < u," cm" -- of «> 'r o en oo 

CM CM r- •.-CM i-CMCMCM 



S -3 -3 



Q. Q. Q. Q. a. 

O ® ® ® S 



_; O) Ol O) 

^^<<co(y3cococo 



Sampling Date 



Fig. 8-26. Influence of citrus pulp (45 t/ac) on Se volatilization 
from Pond 11, <esterson Reservoir. 



8-38 



seasonal effect with the warmer temperatures promoting Se volatilization. 
The addition of citrus + N, citrus + Zn, or citrus + N + Zn did not 
enhance volatilization over citrus alone (Figs. 8-27 to 8-29). The 
average emission rate of volatile Se was 2.80, 2.26 and 3.68 yg m"^ h~\ 
respectively, with these treatments. However, again it was evident that 
the warmer temperatures promoted volatilization upon these citrus 
amendments. 

Proteins 

Two proteins were assessed for enhanced volatilization. The appli- 
cation of gluten (6/15/88) promoted the methylation reaction with an 
emission rate of 3.47 to 15.94 (avg. = 10.57) uQ m"^ h"^ However, 
casein was applied thereafter (7/28/88 and 9/19/88). With an emission 
rate of 1.78 to 120.40 (avg. = 29.93) yg m"^ h"^ casein was the most 
stimulatory of all the amendments tested. On 9/19/88 casein was 
applied again to each of the subplots. Figure 8-30 illustrates the flush 
of volatile Se being released at the onset of each application (9/23/88 
and 9/28/88). Casein enhanced the volatilization rate 13.4-fold over 
the moist treatment and 37.4-fold over the background controls. Prelimi- 
nary laboratory studies have revealed that casein increases the solu- 
bilization of Se by increasing mineralization of organic Se, thus making 
the native Se more available for microbial uptake. The primary limita- 
tion in Pond 11 appears to be the availability of bound Se for volatili- 
zation. Much of the Se is tied up in the organic matter and must be 
released (mineralized) before volatilization. The application of 
proteins such as gluten and casein enhances mineralization of Se and 
provides the needed C and energy for methylation. 



8-39 



E 
o 



11 



10 - 



9- 



8- 



7- 



6 - 



5- 



4- 



3 - 



SUBPLOT 
15 




2 " ^ ^; in ^i rri 



1 - 




S = = 

^ Q -5 -3 



on 


m 


m 


m 


m 


m 


00 


00 


00 


00 


oo 


00 


CO 


00 


CO 


00 


00 


00 


00 


00 


00 


00 


00 


00 


00 


00 


00 


00 


00 


oo 


00 


CO 


CO 


co" 


CVJ 


cvj" 


cm" 

CM 


oo" 

CM 


o> 


oo" 


en" 

CM 


00 


CM 


r~ 


in 


CM 


■^ 


ctT 

CM 


to 
2 




2 


a. 
< 


w 
CL 

< 


a. 

< 




2 




c: 

-3 


c 

-3 


3 


"3 


3 

< 


3 

< 


en 

3 

< 



00 
CO 


00 
00 


00 
00 


oo 
oo 


00 
00 


o> 


t" 


o" 

CM 


CO 

CM 


co" 

CM 


Q. 
0) 
CO 


d. 

CO 


d. 

(0 
CO 


d 

CO 


d. 

<9 
CO 



Sampling Date 



Fig. 8-27. Influence of citrus + N on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-40 



cr 

(0 




r**r^GOooQococoooooooooGOoo®®®®®QOQOoocoao®®co®® 
aoaoooQOaoaoooooooGoaocoGO^^^^^QOGoaoooGOOoaoaoooao 



a> 


CO 


•«r 


«nJ 


m 


TT 




rt 


> 
o 


d 

(D 

o 


c 

(TJ 

-3 


c 

(TJ 

-5 


J3 
0) 
U. 


U. 


Ll. 


2 



CO — . C\J CNJ CO 
^ oi ^ CVJ C\J 



o> 00 CO 00 CO t«^ in" <M ■^" o>" 

^ CM CM ,- T- 04 



C3» 



■T O CO 00 
•.- CM C\J CM 



>. >^ >. _: 

!r >:; J; to (TJ « ^ 

Q. Q. Q. ^ ^ ^ _3 

< < < 



S S 2 



.^ _^ o> O) o> 
^^<<<cO(73cna3co 



a a a C3. Q. 

® (D ® O ® 



Sampling Date 



Fig. 8-28. Influence of citrus + Zn on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-41 



O) 




Sampling Date 



Fig. 8-29. 



Influence of citrus + Zn + N on Se volatilization 
from Pond 11, Kesterson Reservoir. 



110 



100 - 



8-42 



90- 



SUBPLOTS 
2 5 9 



80- 



(A 



CM 

< 




< 



d> 

3 
< 



a. 
o 

CO 



a 

o 

CO 



o 

CM 

cL 

9 
CO 



m 
d 

(D 
CO 



OS 
CM 

d. 

CO 



Sampling Date 



Fig. 8-30. Influence of casein on Se volatilization 
from Pond 11, Kesterson Reservoir. 



8-43 



Further tests are needed to determine how crude proteins such as soybean 
meal, cottonseed meal and safflower meal which are readily available 
would compare in promoting Se volatilization. 

San Luis Drain Sediment 

The sediment was taken out of the drain and mixed in a cement truck 
to homogenize the material before it was deposited at Kesterson (Pond 4). 
The wet sediment was then air-dried on a plastic sheet and mixed thor- 
oughly before being placed 6" high in S'xS'xl' open PVC boxes (50 kg 
box"^. The treatments consisted of moist only, straw + N, citrus pulp, 
citrus + Co (C0CI2), gluten, casein, albumin and cottonseed meal. The 
application rates of each of these treatments are described in detail in 
Chapter 5. The sediments were treated and watered on 9/19/88. Volatile 
Se was monitored on 9/22/88, 9/26/88, and 9/29/88 with the same sampling 
chamber as described in Chapter 6 except with dimensions of 14" x 14" x 
8" (196 in^). 

Sediment Characterization 

The properties of this sediment are as follows: pH, 8.10; organic 
C, 17.6 g kg"^; total N, 1.06 g kg"^ EC^, 23.3 dS m" ^ SAR, 15; ESP, 
17%; B, 17 mg kg"^; total Se, 87 mg kg"^; sand, 45%; silt, 36%; and 
clay, 19%. 

Irrigation and Organic Amendments 

Although only three sampling periods are included in this report 
because of the deadline of submission, we are continuing to monitor 



8-44 



the emission flux. After 3 days, little volatile Se was released by 
the treatments, the one exception being casein (102 ug Se m~^ h"^) 
(Table 8-3). Volatile Se rates with all other treatments ranged from 
21 to 40 yg Se m"^ h"^. The background emission flux was 5 ug Se m~^ h" ^ 
The rates began to dramatically increase after 7 and 10 days of treat- 
ment. At the 7-day interval the release of volatile Se ranged from 50 
(straw + N) to 858 ug Se m"^ h"^ (albumin). All the proteins applied 
strongly stimulated Se volatilization which agrees with our laboratory 
study (see Chapter 3). The most effective organic amendments after 7 
days of application were the following: albumin > casein > gluten > 
cottonseed meal. After 10 days, a relatively high emission rate of vola- 
tile Se was measured from the moist-only treatment (603 uQ Se m"^ h"^). 
This rate is considerably higher than the rates we have detected from 
the moist-only subplots in Pond 4; however, the Se content (87 mg kg"^) 
in the San Luis Drain sediment is also greater than the median value of 
39 mg kg"^ soil in Pond 4. It is evident from our emission data of Ponds 
4 and 11 that the amount of volatile Se released is highly dependent on 
the concentration of Se in soil. 

The application of straw + N (NH^NOg) with an approximate C:N ratio 
of 10 strongly inhibited microbial volatilization of Se (Table 8-3). 
This treatment was included in the experimental design because other 
laboratory studies indicated that straw (salt grass clippings plus N fer- 
tilizer) enhanced the volatilization rates (Amundson et al . , 1988). 
Previous work in this laboratory has established that low levels of N 
in the presence of added C slightly stimulates alkylselenide production, 
but moderate to high levels of N inhibit volatilization (Karlson and 



8-45 



Table 8-3. Influence of specific treatments on volatilization of 
selenium from the San Luis Drain sediment. 





Volatile 


Se (ug m~ \ 


rM 


Treatment 


3 days 
(9/22/88) 


7 days 

(9/26/88) 


10 days 
(9/29/88) 


Moist 


32.9 


140 


604 


Straw + N 


24.5 


50 


269 


Citrus pulp 


23.9 


111 


622 


Citrus + Co 


25.8 


309 


753 


Gluten 


39.8 


320 


■ 1109 


Casein 


101.9 


738 


1014 


Al bumi n 


22.7 


858 


1258 


Cottonseed meal 


20.8 


224 


1029 



8-46 



Frankenberger, 1988b). The San Luis Drain sediment appears to be rela- 
tively high in its N content. The straw + N amendment was the only 
treatment that inhibited volatilization of Se (55% inhibition). After 
10 days, the effect of citrus was not evident under short-term incuba- 
tion, as was expected since decay is required to enhance volatilization. 
However, citrus plus Co showed some enhancement (25%) most likely because 
Co serves as a cofactor in the methylation reaction. Among the proteins, 
the following amendments were the most stimulatory after 10 days compared 
with the moist-only treatment: albumin (2.1-fold) > gluten (1.8-fold) > 
cottonseed meal (1.7-fold) and casein (1.7-fold). Further monitoring 
is needed to determine the natural emission flux under moist conditions 
and the length of time each of the amendments can maintain high vola- 
tilization rates. Long-term monitoring is needed to determine if C will 
be a limiting factor and to establish the frequency of amendment appli- 
cations required to maintain satisfactory levels of Se volatilization. 

Influence of Temperature 

A laboratory study was conducted to determine the influence of 
temperature on the biomethylation of Se in soil (see Chapter 3). The 
rate of Se methylation increased with increasing temperature (5-25°C). 
Volatilization of Se had a temperature optimum of 35°C which is comparable 
to methylation of mercury (Callister and Winfrey, 1986). In terms of 
thermodynamics, the average Q^q was calculated to be 2.60 which is with- 
in a range commonly reported for biological processes. That is, for 
every 10°C rise in temperature, the rate of biomethylation of Se 
increased 2.60-fold. 



8-47 



The diurnal activity of volatile Se production in the field was 
monitored on 10/23/87, 2/5/88, and 9/1/88 (Figs. 8-32 to 8-36). Results 
indicate that the peak of activity is during mid-afternoon. On 10/23/87 
the highest volatile Se emission rate from subplot 63 (citrus, Zn, N) 
(363 ug m"^ h"^) occurred at 1300 h, from subplot 61 (citrus) at 1500 h 
and from subplot 65 (molasses) at 1100 h (Fig. 8-32). 

During the month of February 1988, volatile Se was monitored from 
three subplots (57, moist; 58, 61, citrus) along with the atmospheric and 
soil temperatures (Figs. 8-33 to 8-35). A diurnal cycle of volatile Se 
emission rates was evident, with the peak in all three plots occurring 
from 1400 to 1600 h, lagging just behind the peak of atmospheric and soil 
temperature readings. This was also evident with the diurnal measure- 
ments of subplots 54 and 63 on 9/1/88 (Fig. 8-36). Linear regression 
analysis was performed between the volatile Se flux measured in February 
and the atmospheric and soil temperatures. In most cases, the corre- 
lated coefficient for estimating the biomethylation rates based upon 
temperature was highly significant at the 5% level (Figs. 8-37 to 8-39). 
The diurnal cycle and the temperature coefficient data indicate that Se 
emission rates are highly dependent on the temperature. 

DISCUSSION 

The field emission rates described in this report may be an 
overestimate of the actual Se evolved being monitored by the 



8-48 



CITRUS 



E 






200 -r 




2 3 4 

nriE OF DAY 



TIME OF DAY: 

1 9-10 a.m. 

2 11-12 a.m. 

3 1-2 p.m. 

4 3-4 p.m. 

5 5-6 p.m. 



'I 

r 



400 



300 



ClTRUS.N.Zn 




2 3 4 

HUE OF DAY 



MOLASSES 



A 
"I 







Fig. 8-31. Diurnal measurements of alkylselenide production in 
October 1987. 



a. 
E 



O 
(A 



KESTERSON Pond 4 Atm Temp 



u 


^w ■ 


l...l 


— 


— 1 




2-5-88 


c 

Ui 

C 


10- 








I.- 


' 






' 


- 




m 




0- 


WW 




: 




_ 












mm 





20 



8Ari 9 10 n 12 IPfl 2 3 4 8 12 4AI1 8 

TIME (hrs) 
KESTERSON Pond 4 Soil Temp 



10 



m 




2-5-88 




IW- 


' 






■ 


'I 




m 


















n 


"^^ 


HH't 










ii'i 


Hm 


<i ii 




•*• 





8AM 9 10 11 12 IPtl 2 3 4 8 12 4AM 8 

TIME (hrs) 



8-49 



KESTERSON Pond 4 Oiumal Sampling 



E 

9 



(A 
Ui 



O 
> 



J\J • 


PLOT 57 Moist 2-5-88 


20- 




Pi 








— 




■■■ 




10- 


m 


— 


_ 






























' ' 


'"' 






rt- 


ii^ 




















Rfi 



8AM 9 10 12 IPM 2 3 4 8 12 4AM 8 

TIME (hrs) 



Fig. 3-32. Diurnal measurements of alkylselenide production from 
subplot 57 in February 1988. 



c 

ui 

C 



z 

UI 



CA 



20 



KESTERSON Pond 4 Atm Temp 



10 



2-5-88 



□ 



20 



8AM 9 10 11 12 IPtI 2 3 4 8 12 4An 8 

TIME (hrs) 
KESTERSON Pond 4 Soil Temp 



10- 















2-5 


-88 






Fl 


^tl 








— " 






WW 








s^ 


I 
•■H 


1 1 


' 


' ' 


" 






r~i 




















'■ii 


;*ut 


Hill 


t- 


'' 


1 

^ 


' 




*"" 






' 


■■ 


Ttl 


lih- 


■ 


1 1 


t.1, 


' 


I 


■ 





8AM 9 10 11 12 1PM 2 3 4 8 12 4AM 8 

TIME (hrs) 
KESTERSON Pond 4 Diurnal Sampling 



E 

m 



(I) 
III 



3W - 


PLOT 58 (Citrus) 2-5-88 


40- 




— 


rn 


■ 




f-i 






n*i 


30- 


















111 




■• 












20- 
























— - 


















1 


10- 


n^ 


;:;■ 
















































:::. 




:■■■■ 


























0-1 


_ 


' 


_ 




_, 


__ 















■:;' 



8AM 9 10 11 12 1Pn 2 3 4 8 12 4AM 8 

TIME (hrs) 



Fig. 8-33. Diurnal measurements of alkylselenide production from 
subplot 58 in Februari' 1988. 



G-51 



C 

H 
C 

< 



E 
ui 

H 



O 



I 






< 
> 



KESTERSON Pond 4 Atm Temp 



20 



10- 



ti 



2-5-88 



a 



SAM 9 10 n 12 1PM 2 3 4 8 12 4Ari 8 

TIME (hrs) 
KESTERSON Pond 4 Soil Temp 



20 



10- 



2-5-88 



8An 9 10 11 12 IPM 2 3 4 8 12 4Ari 8 

TIME (hr3) 
KESTERSON Pond 4 Oturnal Sampling 

50 



30- 



PLOT 61 (Citrus) 2-5-88 


n 




n 




1 — 1 
















^ 


^^ 














p- 




- ^!:-i 






















r— 1 


^p,- 


'■ ■ 








, 










1- 









20- r-1 



10 



8AM 9 10 11 12 1PM 2 3 4 8 12 4AM 8 

TIME 



Fig. 3-34. Diurnal measurements of alkylselenide production from 
subplot 61 in February 1988. 



8-52 



a" 

CO 



CO 
Ui 

< 

o 

> 




SAM 9 10 11 12PM 12 3 4 



TIME (hrs) 



800 



600 - 



CO 



M 
lU 

< 

O 

> 



400- 




200- 



8AM 9 10 11 12PM 12 3 4 



TIME (hrs) 



Fig. 8-35. Diurnal measurements of alkylselenide production from 
subplots 54 and 63 in September 1988. 



8-53 



PLOT 57 



y - .629s * 5.124. R-9«««r«d: .553 



i 

< 
> 




8 10 
ATM TBV 




Fig. 8-36. Linear regression analysis of alkylselenide production 
in subplot 57 and atmospheric and soil temperature. 



PLOT 58 



y - t.215a ♦ 11. 792. R-4qttsr«d: .442 



E 
f 

< 



45. 
40 




6 8 10 

ATM TE^P 



12 14 16 18 



E 

? 

< 



y - 1 .999x * 5^22. R-3qaar«d: .626 



8 10 
SoUTemo 




14 



16 



Fig. 8-37. Linear regression analysis of alkylselenide production 
in subplot 58 and atmospheric and soil temperature. 



8-55 



PLOT 61 



y - 1 .602x ♦ 6^08, R-sqttar««: .828 



< 




8 10 

ATM mv 



y - 2.1141 ♦ 2.631. R-4qaar«4: .755 



2 
E 

? 

2 

< 



8 10 

Soil TentQ 




16 



Fig. 3-38. Linear regression analysis of alkylselenide production 
in subplot 61 and atmospheric and soil temperature. 



8-56 



vacuun nethod. Sorie gaseous Se may be taken up outside the periphery 
of the chamber upon lateral flow beyond the sampling area. The 
sampling technique (forced flow of soil gas) may also interfere with 
the natural resorption of DMSe and possible overestimate the true 
DMSe flux from the soil to the atmosphere. Also it should be noted 
that a 24-h average emission reading would be less than mid-day 
readings because of the cooler temperatures at night. Attempts are 
now being made to place passive activated C traps to capture the 
alkyl selenides released in the field on long-term monitoring 
(>2-3 days). 

It should also be noted that the sampling device was tested for 
recovery rates in the field by injecting DMSe spikes with an air 
flow of 2 L min"^. Fifty yg of DMSe-Se were injected into the 
sampling chamber via a rubber septum. Traps were analyzed according 
to standardized procedures described in Chapter 7. Recovery was 18.4%. 
It is speculated that DMSe is lost by adsorption to the interior 
surface of the sampling chamber or to soil. All the sampling cham- 
bers were coated with Teflon (Fluoroglide spray, Norton Performance 
Plastics, Wayne, NJ) to reduce adsorption. 

The May sampling readings are conspicuously lower than those of 
April and June which bring down the average yearly emission rates of 
each treatment. Our field manager decided independently at that time 



8-57 



to press the sampling chambers deep into the soil, not allowing suffi 
cient headspace for evolution of the alkylselenides. His reasoning 
behind this action was to extend the sides of the inverted box into 
greater depth so that soil adjacent and outside of the chamber would 
have a minimal influence. All the volatile emission readings in May 
are extremely low. This was corrected in June 1988. 



9-1 



CHAPTER 9 

CONTROLLED STUDIES IN MONITORING SELENIUM 
VOLATILIZATION FROM TREATED KESTERSON SEDIMENTS 

Introduction 



The purpose of this study was to simulate the conditions occurring 
in the field at Kesterson Reservoir with greater trapping efficiency of 
the released alkylselenides. There are many potential problems in 
measuring volatile Se in the field as indicated in Chapter 8. In this 
particular study, high recovery of the gaseous Se was demonstrated with 
excellent precision and accuracy. The study was conducted in the 
greenhouse to operate under fluctuating temperatures, diurnally and 
seasonally. 

Soil was collected nearby our existing plot in Pond 4 and treated 
with the same field amendments as described in Chapter 6. Sediments at 
Kesterson contain substantial quantities of organic and amorphous Se, 
in addition to the water-soluble species. Compared with Se(IV) and Se(VI), 
the microbial formation of alkylselenides from organo-Se and elemental 
Se species is expected to vary (Doran, 1982), hence Se volatilization 
from Kesterson sediments might occur at different rates than those 
reported in other studies. In particular, the microbial reaction is 
likely to become Se-substrate limited, once the organic and the water- 
soluble Se pools have been consumed. 



9-2 



This study was undertaken to determine the Se volatilization rates 
from Kesterson sediments under long-term conditions, and the effect of 
incorporation of economically available carbon sources. 



MATERIALS AND METHODS 
Soil Incubation 

The selenium-contaminated sediment was collected at Pond 4 of 
Kesterson Reservoir (Merced County, California). Its properties were 
determined as follows: clay, 15.7%; sand, 60.7%; water content at 
-33 kPa (2.5 pF), 0.53 L kg'-^; total N, 2.52 g kg"-^; total organic C, 
37.0 g kg"-^; pH 8.04; ECg (saturated paste), 22 dS m"-^; total Se, 60.7 
mg kg" . The soil was sieved (<2 mm) and homogenized. Its properties 
(Table 9-1) were determined according to standard procedures (Page et 
al., 1982; Klute, 1986). 

Soils were incubated in closed systems with forced air exchange 
(Karlson and Frankenberger, 1988a). In 500-mL Erlenmeyer glass 
flasks, 100-g samples were maintained at -33 kPa (2.5 pF) water 
content. Each headspace was continuously flushed with moistened air 
at approximately 50 mL min"'^. The experimental apparatus was located 
in the greenhouse, where temperatures followed daily and seasonal 
patterns. In February of 1988, at the start of the experiment, air 
temperature extremes were 33°C (day) and 16°C (night). In early 



9-3 



September of 1988, the maxima and minima of the season were observed 
with typical values of 37°C (day) and 21°C (night). Soil temperatures 
were highest in the early afternoon measuring approximately 7°C above 
air temperature and lowest in the early morning with readings identical 
to the air temperature. 

Soil subsamples were analyzed for total Se prior to the experiment. 
Subsamples were digested by sequential treatment with concentrated 
nitric acid (HNO3), hydrogen peroxide and hydrochloric acid (HCl) 
(Bakhtar et al . , 1988). The digests were taken up in 6 M HCl , boiled 
in a water bath (100°C) for 1 h to reduce Se(VI) to Se(IV), and analyzed 
on a Varian AA-10 atomic absorption spectrophotometer (AAS) equipped 
with a VGA-76 continuous-flow hydride generator. Instrument parameters 
were set as follows: wavelength, 196.0 nm; acetylene flow, 2.4 mL min"^; 
air flow, 6.3 mL min"^; sample flow, 8 mL min"^; concentrated HCl flow, 
1.2 mL min"^ sodium borohydride, 0.6% (w/v) , 1.2 mL min; N^ purge, 
90 mL min"^. 

Soil Amendments 

At the onset of incubation, soils were amended with citrus pulp 
(orange peel), grape pomace, cattle manure, barley straw plus N, or 
pectin (Table 9-1). Citrus pulp was applied as a sole treatment or 
in combination with Zn (0.227 g kg"^ soil as ZnS04-7H20), N [0.947 g 
kg'^ soil as (NH„)2S04], Co (50 mg kg"^ soil as CoCl2-6H20), or a 15 mL 



9-4 



Table 9-1. Organic materials used as soil amendments. 



Material 


Source 


Prepa- 
ration 


H2O 


Organic 
matter 




Total N 








g 


kg"^ dry 


wt, 


» — — — — — — — — 


Chitin 


Sigma, St. Louis, MO 












Citrus pulp, 
fresh 


Sunk i St Growers, 
Ontario, CA 


ground 


3831 


973 




19.0 


Grape pomace, 
fresh 


Gallo Winery, 
Modesto, CA 


ground 


1179 


953 




19.8 


Feedlot 
manure 


Harris Feeding Co. , 
Coalinga, CA 


ground & 
sieved 


376 


369 




18.4 


Barley straw 
plus N 


(locally) 
(NHjgSO^ 


chopped 


58 


ND 




8.7 



''Not determined 



9-5 



aqueous suspension of Acremonlum fald forme containing 1.9 x 10^ propa- 
gules mL"^. The fungus had been cultured on Sabouraud's dextrose agar 
(Difco, Detroit, MI). 

The quantities of organic amendments had been chosen to match those 
rates applied in the field at Kesterson on a dry weight basis (straw 
plus (NH^)2S04-N, 14.9 g kg"^ and 0.4695 g kg"^ respectively; manure, 
106.6 g kg"^; and citrus, 45 g kg"^ soil). The grape pomace application 
rate was equivalent to the citrus application. The applied quantity of 
chitin and pectin (4.5 g kg"^ soil) amounted to 10% of the citrus appli- 
cation on a dry weight basis. Nitrogen additions had been calculated to 
adjust the C/N ratio of the respective organic amendment to 10. Organic 
amendments were repeated periodically, while Zn, Co, N and the inoculum 
were only included with the initial application. Each treatment con- 
sisted of four replicates. The control was only moistened. 

Determination of Se Evolution 

Volatile Se was trapped with activated carbon (C) filters (1.08 g 
activated C per filter) inserted in the air stream (Karlson and 
Frankenberger, 1988a). The traps were eluted with 12 mL of methanol 
(MeOH), the eluate being mixed immediately with 6 mL of concentrated 
HNO3. After evaporation of MeOH and HNO3 in a water bath (85°C), the 
trap extracts were analyzed for Se by AAS, using the same procedure as 
for soil digests. The dominant Se species in the eluate was identified 
as DMSe by gas chromatography/mass spectrometry (Karlson and 
Frankenberger, 1988a), and in the HNO3 digest as Se(VI) by paper 
chromatography (Tuve and Williams, 1961). 



9-6 



Overall recovery was determined to be 80% by spiking traps with 
known amounts of gaseous DMSe using a gas-tight calibrated syringe. 
Gas standards were prepared by evaporating a small weighed quantity 
of DMSe in a 10-L glass bottle and making dilutions of this stock 
standard in smaller glass containers using a gas-tight calibrated 
syringe. All glass containers had been silanized and were capped with 
Mininert teflon septa (Dynatech, Baton Rouge, LA). Selenium analyses 
of activated C extracts were quality-controlled through duplicate 
determinations and the use of Se standard spikes. 



RESULTS 

Among the treatments applied to the sediment, there appeared to be 
four major groups influencing Se volatilization (Fig. 9-1 and Table 9-2) 
(1) Grape pomace inhibited Se volatilization by approximately 60% com- 
pared with the moist-only treatment. (2) Chitin and straw plus N 
overall had little effect on Se volatilization. (3) Amendments with 
manure or pectin increased the overall volatilization 2.8-fold over the 
control; however, pectin only began to enhance Se evolution rates after 
the second and particularly the third application. With the manure 
treatment, there appears to be a discrepancy between the Pond 4 field 
emission data and this study; however, manure did stimulate alkyl- 
selenide production in Pond 11 over the moist-only subplots by 37% 
during the yearly cycle (see Chapter 8). After 198 d of incubation. 



9-7 



35 



Chitin 



Citrus 



40 



Manure 



Straw + N 



Cumulative' 




I ' ■ ' ■ I ' 
100 125 



I I I I I I I I I I 



200 



Days 



Fig. 9-1. Selenium volatilization from Kesterson soil (Pond 4) 
in response to different amendments. 



9-8 



Table 9-2. Analysis of variance of cumulative selenium volatilization 
from Kesterson soil as affected by different amendments. 



Source df SS MS 

Between treatments 
Within treatments 
Total 



9 


3466.8 


385.2 


19.205*** 


30 


601.7 


20.1 




39 


4068.5 







Comparison between Control (Moist) 

and: Dunnett's t-value: 



Chitin 0.267 

Citrus 6.491*** 

Grape 1.016 

Manure 3.500* 

Straw + N 0.872 

Pectin 3.431* 

Citrus + Zn 8.187*** 

Citrus + Zn + N 5.076** 

Citrus + Zn + N + Acremonium 5.443** 



9-9 



approximately 18% of the native Se was lost with this group of amend- 
ments. (4) The fourth group, citrus pulp alone and citrus pulp in com- 
binations with Zn, N and A. falciforme , stimulated Se volatilization 
3.5- to 5.3-fold over the control. After 198 d of incubation, approxi- 
mately 26 and 32% of the native Se was lost (compared with 6% of the 
unamended control) by the citrus pulp alone and citrus plus Zn treat- 
ments, respectively. However, in terms of weekly rates, the three 
citrus pulp combinations exceeded the control only after the second 
application. Furthermore, during the first 4 weeks, the two citrus pulp 
combinations with Zn plus N produced volatile Se at approximately one- 
half the rate of the control. This response appears to be due to the 
added N amendment since citrus plus Zn dramatically promotes Se 
methylation. 

The rates of Se evolution increased in response to the second and 
the third application of only six of the 10 treatments (manure, pectin 
and the four citrus combinations). With the four citrus combinations, 
those increased rates were maintained for 5 to 8 weeks. The volatili- 
zation rates during this period were approximately 2.5 to 3 times 
higher than following the initial application. 

DISCUSSION 

The four citrus combinations, manure and pectin were the only 
treatments which showed a positive response to repeated applications. 



9-10 



The increased rates were observed up to two months after the first 
amendment and, with the exception of the pectin and the citrus-only 
treatments, did not decrease significantly with time. Volatilization 
rates had been reported to decrease within a few weeks after treatment 
with pectin, and again to increase sharply with each renewed application 
(Karlson and Frankenberger, 1988b; Chapter 2). These curvilinear pat- 
terns had been interpreted as being caused by the limited availability 
of C as a source of energy for the microbial methylation reaction. 
Within a few weeks, the C sources had been depleted by the soil 
microflora and needed to be replenished. In this study, with most of • 
the stimulatory treatments, the production of volatile Se did not 
follow a curvilinear pattern, but appeared to be almost linear. This 
indicates that the more complex C sources (as opposed to the poly- 
saccharide, pectin) were being utilized by the soil microflora more 
slowly and at a steady-state rate. Apparently the amount of organic 
materials applied initially were below optimum in terms of maximized Se 
removal. The strong rate increase upon the second application of manure 
and all four citrus combinations supports this premise. With chitin and 
the unamended control, volatilization rates decreased with time during 
the initial phase of incubation. Apparently the indigenous C supply was 
depleted within several months, and the addition of chitin did not pro- 
vide a readily available energy source, hence there was no stimulation 
following chitin reload. 



9-11 



Since microbial processes are temperature-dependent, the enhance- 
ment in volatilization rates after the second application of citrus 
(i.e., after May 19) theoretically might be attributable to an increase 
in temperature during the summer months. A temperature coefficient 
(Qj^q) of 2.60 has been reported for Se volatilization from Kesterson 
soil (Chapter 3). The air temperature was recorded continuously at the 
location of this experiment. Temperature was controlled throughout 
the day and night periods, with only minor increases as the season 
progressed. Using the daytime temperatures and the reported Q,^,, the 
volatilization data for the citrus plus Zn treatment were standardized 
for the first-month (February) temperatures, i.e., Se evolution was 
estimated for what it would have been if temperatures had not changed 
with the season. Figure 9-2 indicates that the actual and standardized 
Se evolution rates were not significantly different, i.e., the increase 
in Se volatilization occurred independently from temperature. 

The combination of citrus pulp with mineral N appeared to exert an 
inhibitory effect on Se evolution. This observation agrees with our 
earlier studies (Karl son and Frankenberger, 1988b) where N addition at 
C/N = 5 to galacturonic acid as a C source was found to inhibit Se 
volatilization. Nitrogen addition was also noted to inhibit volatili- 
zation of Se in the field with the straw + N treatment in Pond 4. 

Also consistent with earlier findings (Chapter 2) is the observa- 
tion that fungal inoculation does not accelerate Se volatilization rates 
significantly. Acremonium falci forme, originally isolated from a 



9-12 



% 



o 

I 



25 



20 



15 



1 



a 
t 

i 5 
I 

i 

z 
e 
d 



+ C 

J- 



y 0-0-°-°-? 



. Citrus +Zn Treatment 

+C 

Tt t I I I I I I I I I I I I I I I I I I I I I 



•o- Kesterson standardized 
••- Kesterson actual 



2/ 

1 1 

/ 8 

8 



2 / 

25 

/ 8 

8 



3/ 

1 

/ 8 

8 



3 / 

24 

/ 8 

8 



4 / 
7/ 
88 



4/ 

21 

/ 8 

8 



5/ 
5 / 
88 



5 / 

1 9 

/ 8 

8 



6 / 
2/ 
88 



6 / 

1 6 

/ 8 

8 



6/ 

30 

/ 8 

8 



7/ 

1 4 

/8 

8 



Sampling Date 



Fig. 9-2. Actual and temperature-standardized Se volatilization 
from Kesterson soil, after amendment with citrus pulp 
and Zn. 



9-13 



seleniferous soil, was shown to volatilize Se in pure cultures (Karlson 
and Frankenberger, 1987) and when inoculated into sterile soil (Chapter 
2). Apparently Kesterson sediments already contain a sufficient popula- 
tion of Se volatilizing organisms, which is not altered by the addition 
of the fungal isolate. 

Further work has been initiated (9/23/88) to test the influence of 
proteins (gluten, casein, cottonseed meal, soybean meal and safflower 
meal) and native vegetation ( Distichlis spicata [saltgrass], Bassia 
hyssupifol ia , Atriplex patula and Typha domingensis ) with and without 
the addition of N on volatilization of Se in Kesterson sediments under 
these controlled conditions. 



10-1 



CHAPTER 10 



DISSIPATION OF SELENIUM FROM THE Ap HORIZON 



Soil Analysis 



Procedure 



Starting with September 11, 1987 all subplots were sampled for soil 
Se on a monthly basis. Within each 12' x 12' subplot, five soil sub- 
samples (A-E) were collected to account for spatial variability. The 
subsamples were spaced approximately 4.25' apart from each other as 
shown below: 




12' 



12' 



Soil samples were collected with a 1" diameter probe to a depth of 6" 
(Ap [plow layer]) (the same depth as the rototiller mixes soil). In 
addition, an initial inventory of the Se distribution versus soil depth 
was taken along 2'-deep profiles at 6" intervals. Profile samples were 
taken from randomly assigned subplots at subsample point C. Upon 
collection, each of the samples was placed in a zip-lock bag, labeled 



10-2 



and packed with blue ice in an ice chest. Once the samples were 
collected, the chest was delivered to CSUF along with the chain-of- 
custody forms. All chain-of-custody records are on file at OCR. The 
entire soil sample was passed through a 2-mm sieve and ground to 
100-mesh. After the sample is thoroughly mixed, splits (10% of *he 
total samples) are mailed to UCR for analysis. All samples are kept 
refrigerated at 4°C. The quality assurance/quality control procedures 
in Appendix C provide the soil digestion procedure (EPA Method 3050) and 
analytical method (EPA Method 270.3) for determination of Se content (EPA 
Methods for the Chemical Analysis of Water and Waste, EPA 600/4-79-020). 
Modifications of the above approved method, together with methods devel- 
oped at UCR are also documented (Appendix C). Samples were analyzed by 
atomic absorption spectrometry (AAS)/hydride generation and reported 
on a dry weight basis. 

Quality Assurance Objectives for Generation of Data 

The data quality objectives for this study are summarized as follows: 



Table 10.1. Data quality objectives. 



Data Quality QA Plan 

Objective How Determined Section Criteria 

Accuracy Reference material 11.1 +^20% of value if result 

is greater than 20 times 
CRDL; + 4 times CRDL 
value if result is less 
than 20 times CRDL 

Accuracy Recovery in spiked 

sample 11.3 80-120% of recovery 



10-3 



Table 10.1. (continued) 



Data Quality QA Plan 

Objective How Determined Section Criteria 

Precision Duplicate analysis 11.2 15% if over 20 times 
of sample CRDL; 20% if 5 to 20 

times CRDL; +1 CRDL if 
less than 5 times CRDL 

Completeness Number of samples 14.3 20-100% of soil samples 
analyzed 95-100% of gas samples 

Representa- Analyze reference 11.1 See criteria for accuracy, 
tiveness materials 

Comparability Split samples also 11.2 See criteria for precision, 
analyzed by UCR 
1 aboratory 

Detection limit Lowest concentration 9.2.1 1.0 mg/kg soil 
level that can be 
determined to be 
statistically dif- 
ferent from a blank 



Internal quality assurance samples (USBR sediment standard reference 
samples) were analyzed to assure accuracy of our analytical technique. 
UCR participated in this program with the use of ICP and AAS. Both 
analyses using the two instruments were in a comparable range to that 
reported by USGS, LBL and CSUF (Table 10-2). 

Among the split samples, UCR and CSUF did not initially agree in 
their results on Se content of the soil samples collected at Kesterson 
Reservoir. UCR consistently had higher numbers, averaging 40% greater 



10-4 



Table 10-2. Analysis of internal quality assurance samples to 
assess accuracy of analytical technique. 



U.S. Bureau of Reclamation 
Sediment Standard Reference Samples 

SRS ID USGS^ LBL^ CSUF3 UCR-ICP'* UCR-AAS^ 

58 (RPD = 2.7%) 56 (RPD = 13.2%) 

94 (RPD = 2.8%) 82 (RPD = 5.46%) 

21 (RPD = 3.2%) 19 (RPD = 2.04%) 

2.1 (RPD = 4.8%) 2.7 (RPD = 2.21%) 



^Analyzed by the U.S. Geological Survey Laboratory Geologic Division. 
Results are based on the analysis of ten randomly selected splits from 
each standard using atomic absorption-hydride generation techniques. 

^Analyzed by Lawrence Berkeley Laboratory three times each using X-ray 
fluorescence techniques. 

^Analyzed by California State University of Fresno using atomic 
absorption-hydride generation techniques. 

"^Analyzed by University of California, Riverside using inductively 
coupled argon plasma emission spectrometry (4 replicates). 

^Analyzed by University of California, Riverside using atomic absorption- 
hydride generation techniques (3 replicates). 



KS-l-S 
(306) 


63 


58 


53 


K-3-S 
(307) 


85 


87 


82 


K-6-S 

(308) 


22 


24 


19 


KS-12-E 
(309) 


2.5 


4.2 


2.5 



10-5 



in Se content. Although the numerical values were consistently higher 
by UCR, both laboratories showed parallel trends in magnitude. In-house 
checks among the laboratories were performed to identify the source of 
the analytical discrepancies. The differences were attributed to the 
methods of processing the soil, extraction procedures and use of 
analytical instruments. At that time, UCR was using an ICP while CSUF 
was using an AAS/hydride generation system. Also UCR was extracting 
their samples with HNO3 for 72 h while CSUF carried out this process 
for 24 h. Both laboratories (since February 1988) are now using the 
same method to process the soil, extraction procedures (see Appendix C) 
and the same type of analytical instrument (AAS) to determine the Se 
content. 

Split samples now show good agreement between CSUF and UCR with the 
acceptance criterion being +_20% RPD (Table 10-3). Samples collected 
from Ponds 4 and 11 were analyzed in duplicate by UCR with an in-house 
average RPD of 6.06%. Among all of the split samples analyzed, the 
pooled averages were 20.98 mg/kg (UCR) and 21.27 mg/kg (CSUF). Inter- 
laboratory RPD between UCR and CSUF was 12.56%. 

Selenium Distribution in Soil Profiles 

Soils were sampled at different depths at both Ponds 4 and 11 to 
determine the distribution of Se (Tables 10-4 and 10-5). At Pond 4, pro- 
file samples were collected on 7/29/87, 11/24-25/87, 1/19/88 and 7/24/88, 
and at Pond 11 on 11/25/87. The results indicate that in July (1987), 90% 
of the total Se within the soil profile was within the upper 6" at Pond 4. 



10-6 



Table 10-3. Quality control of soil samples from 
Kesterson Reservoir. 



PROJECT: KESTERSON SELENIUM STUDY 
SAMPLE SET: Check on CSUF 
ANALYZED BY: Roberta Wright, UCR 

UCR Interlaboratory 
UCR • CSUF Precision comparison 
Site ID avg. avg. RPD* RPD 

— mg kg"^- % % 



K1C4 3.91 3.48 3.32 

K2C4 6.36 5.62 3.14 

Ki,C^ 2.20 3.92 8.65 

h^^ 4.74 3.93 10.97 

KsCt, 5.44 5.03 0.55 

KioC^ 3.91 3.26 4.85 

Ki2C^ 5.05 4.71 4.15 

K^C^ 3.58 3.50 5.58 

K16C4 4.89 3.62 0.61 

KisCh 3.10 2.48 9.03 

KaoC^ 3.20 3.53 3.75 

K22C4 2.98 3.15 1.00 

K2i,C^ 2.29 2.25 • 3.06 

K26C^ 2.66 2.37 ' 6.37 

K28C4 4.01 3.88 10.47 

K3oC4 4.86 4.16 16.46 

K51C4 17.02 21.42 0.82 

K52C4 68.42 51.24 6.97 

KsaC^ 41.11 41.17 0.41 

Ks-^C^ 27.96 28.38 14.66 

KssC^ 84.26 86.50 6.31 

KseCi, 97.22 86.06 6.21 

KsyC^ 60.37 51.83 3.52 

KsbCi, 32.55 39.88 18.12 

KsgC^ 31.18 30.28 2.37 

KeoCi, 28.67 26.34 4.53 

KeiC^ 42.81 40.97 16.77 

K62C1+ 63.09 61.02 2.96 

K63C4 56.15 48.28 6.99 

Kgi+C^ 42.96 35.42 3.60 

KesCi, 54.88 47.00 3.06 

K66C4 30.76 29.51 2.14 



11 


.64 


12 


.35 


56 


.21 


18, 


.68 


7, 


.83 


18. 


.13 


6, 


.97 


2. 


.96 


29. 


.85 


22. 


.22 


9, 


.81 


5, 


.55 


17, 


.62 


11, 


.53 


3. 


.30 


15. 


.52 


20. 


,25 


28. 


.71 


0. 


.15 


1, 


,49 


2. 


,62 


12. 


.18 


15. 


.22 


20. 


.24 


2. 


93 


8. 


47 


4. 


39 


3. 


34 


15. 


07 


19. 


24 


15. 


47 


4. 


15 



10-7 



Table 10-3. (continued) 



PROJECT: KESTERSON SELENIUM STUDY 
SAMPLE SET: Check on CSUF 
ANALYZED BY: Roberta Wright, UCR 



UCR 
Site ID avg. 





UCR 


Interlaboratory 


CSUF 


Precision 


comparison 


avg. 


RPD* 


RPD 




% 


% 


4.30 


3.0 


1.4 


4.17 


10.5 


19.2 


4.47 


10.9 


19.9 


41.59 


23.1 


15.7 


60.0 


0.2 


12.1 


6.33 


12.2 


4.6 


4.09 


3.5 


18.4 


4.47 


9.0 


13.9 


68.16 


2.3 


24.7 


34.16 


1.5 


4.7 


4.89 


7.7 


16.6 


4.06 


14.1 


23.0 


2.81 


3.6 


23.4 


50.63 


5.1 


11.0 


33.45 


17.6 


14.1 


5.29 


5.2 


2.1 


3.36 


0.7 


21.4 


4.81 


1.5 


20.1 


71.6 


5.9 


13.3 


5.02 


7.46 


6.56 


3.79 


3.03 


4.39 


3.47 


5.95 


4.72 


42.37 


0.27 


13.13 



-mg kg' 



KlOi 4.24 

K14: 3.44 

K22) 3.66 

K581 35.95 

K64i 53.15 

K3^ 6.05 

Ki6p 3.40 

K202 3.89 

K552 53.20 

K6O2 27.00 

K63 4.14 

Kiu 3.22 

K240 2.22 

K523 45.35 

K6O3 29.05 

K4. 5.18 

K184 2.71 

K2I4 3.93 

K574 62.65 

KSr 5.36 

K165 3.96 

K25q 3.31 

K6I5 37.15 



10-8 



Table 10-3. 


(continued) 








PROJECT: 


KESTERSON 


SELENIUM 


STUDY 




SAMPLE SET: 


Check on CSUF 






ANALYZED BY: 


Roberta Wr 


Mght, UCR 












UCR 


Interlaboratory 




UCR 


CSUF 


Precision 


comparison 


Site ID 


avg. 


avg. 


RPD* 


RPD 




ng kg" 


•1 


% 


% 


^l6 


5.53 


5.84 


1.06 


5.45 


K66 


3.51 


3.72 


2.77 


3.00 


^166 


3.76 


3.81 


7.42 


1.32 


^536 


34.60 


37.48 


1.73 


7.90 


^586 


28.15 


30.78 


1.07 


8.93 


^88 


5.26 


5.64 


15.20 


6.97 


^128 


3.96 


4.03 


5.05 


1.75 


K2O8 


3.70 


3.38 


7.75 


9.04 


^548 


28.30 


25.41 


9:19 


10.76 


Keig 


37.65 


41.62 


3.45 


10.02 


K79 


3.60 


4.89 


6.67 


30.39 


KI89 


2.67 


2.99 


8.24 


11.31 


K2I9 


3.44 


3.54 


2.33 


2.87 


K5I9 


16.10 


22.85 


6.21 


34.66 


K639 


43.60 


41.54 


0.00 


2.42 



10-9 



Table 10-4. Profile distribution of selenium at Pond 4, Kesterson 
Reservoir. 











Selenium content (mg kg"^ soil) 






Subplot 


Depth 


Jul.] 


L987 


Nov. 1987 Jan. 88 


Jul.; 


88 




(in.) 


(29) 


(24-25) (19) 


(24) 


51 


0- 


■6 


4.7 


(2.79)* 


17.1 (3.05) 


16.7 


(5.80) 


51 


6- 


-12 


ND** 


ND 


2.1 




51 


12- 


■18 


ND 




ND 


3.4 




51 


18- 


•24 


ND 




ND 


ND 




52 


0- 


■6 


17.9 


(1.90) 


17.0 (6.65) 


5.6 




52 


6- 


■12 


3.1 ( 


:i0.53) 


ND 


ND 




52 


12- 


■18 


ND 




4.3 (1.87) 


1.0 




52 


18- 


■24 


ND 




ND 


ND 




53 


0- 


■6 


16.5 


(6.56) 


37.5 (2.62) 


12.1 




53 


6- 


■12 


5.9 


(0.00) 


ND 


1.2 




53 


12- 


■18 


3.1 


(6.37) 


ND 


9.5 




53 


18- 


■24 


ND 




ND 


1.4 




54 


0- 


■6 


8.8 


(5.23) 


7.0 (4.16) 


15.8 


(7.69) 


54 


6- 


•12 


ND 




ND 


1.1 




54 


. 12- 


■18 


ND 




ND 


4.1 




54 


- 18- 


■24 


ND 




ND 


1.3 




55 


0- 


-6 


18.1 




33.4 (2.70) 


25.1 




55 


6- 


-12 


1.8 




1.7 (4.68) 


2.4 




55 


12- 


•18 


ND 




ND 


3.3 




55 


18- 


•24 


1.3 


(3.95) 


ND 


ND 




56 


0- 


■6 


23.5 


(0.64) 


34.3 (4.20) 


19.8 




56 


6- 


-12 


1.8 1 


(14.53) 


ND 


2.3 




56 


12- 


-18 


ND 




3.7 (0.82) 


13.6 




56 


18- 


-24 


ND 




ND 


1.2 




57 


0- 


-6 


15.0 


(1.40) 


12.6 (6.29) 


18.5 




57 


6- 


-12 


ND 




ND 


4.6 




57 


12- 


-18 


ND 




2.9 (3.84) 


3.8 




57 


18- 


-24 


1.3 


(2.41) 


ND 


1.6 




58 


0- 


-6 


57.3 


(5.90) 


17.0 (3.48) 


11.8 


(16.19) 


58 


6- 


-12 


1.8 


(23.10) 


ND 


12.9 




58 


12- 


-18 


1.0 


(2.93) 


1.1 (2.79) 


5.0 




58 


18- 


-24 


ND 




1.1 (4.65) 


3.9 





'Figures in parentheses indicate RPD, % 
""ND, not detected (<1 mg kg"M 



10-10 



Table 10-4. 


(continued) 














Depth 
(in.) 


Sel 


eniuin c 


;ontent 


(mg kg" ■^ soil ) 






Subplot 


Jul. 1987 
(29) 


Nov. 1987 

(25) 


Jan. 88 

(19) 


Jul. 88 
(24) 




59 
59 
59 
59 


0-6 
6-12 
12-18 
18-24 


20.5(11.02) 
ND 
ND 
ND 


15.1 
1.0 
1.6 ( 
ND 


(8.52) 

(4.88) 

;i3.92) 


34.1 (2.12) 
5.2 (14.08) 
ND 
ND 


15.9 
3.7 
3.2 
3.9 




60 
60 
60 
60 


0-6 
6-12 
12-18 
18-24 


10.2 (3.13) 
ND 
ND 
ND 


16.6 
2.5 

ND 
ND 


(1.69) 
(0.79) 




10.1 
1.4 
2.3 
ND 




61 
61 
61 
61 


0-6 

6-12 

12-18 

18-24 


18.1 (0.39) 
ND 
1.5(11.76) 
ND 


15.9 
ND 
1.1 
ND 


(1.20) 
(3.77) 




14.8 (12.37) 
2.1 
3.4 
ND 


62 
62 
62 
62 


0-6 
6-12 
12-18 
18-24 


16.8 (0.18) 
ND 
1.4 (9.1) 
ND 


31.3 
1.56 
ND 
ND 


(3.26) 
(3.85) 




12.6 
3.1 
ND 
ND 




' 63 
63 
63 
63 


0-6 
6-12 
12-18 
18-24 


10.2 (6.89) 
ND 
ND 
ND 


51.8 
2.43 
1.16 
ND 


(1.80) 
(2.06) 
(4.33) 


29.6 (37.68) 

12.5 (14.78) 

1.23(10.61) 

3.53 (3.97) 


15.0 
2.58 
4.33 
1.08 


31.7 
2.1 
2.3 

ND 


64 
64 
64 
64 


0-6 
6-12 
12-18 
18-24 


4.6(20.59 ) 
2.7 (3.29) 

ND 

ND 


9.52 

ND 

2.66 

ND 


(5.04) 
(0.75) 




6.6 
1.5 
ND 
2.0 




65 
65 
65 
65 


0-6 
6-12 
12-18 
18-24 








39.5 (9.68) 
15.5 (1.48) 
2.2 (2.32) 
ND 


9.1 
ND 
3.9 
2.8 




66 
66 
66 
66 


0-6 
6-12 
12-18 
18-24 








32.2 (7.02) 
4.2 (2.38) 
3.4 (4.07) 
1.7 (0.58) 


8.0 (2.47) 

1.2 

4.8 

ND 



♦Figures in parentheses indicate RPD, % 
**ND, not detected (<1 mg kg" ) 



10-11 



Table 10-5. Profile distribution of selenium at Pond 11, 
Kesterson Reservoir. 







Selenium content (mg kg"^ 


soil) 


Subplot 


Depth 
(in.) 


Nov. 
(25) 


1987 




2 


0-6 


5.59 


(3.22) 




2 


6-12 


1.28 


(11.76) 




2 


12-18 


ND 






2 


18-24 


ND 






4 


0-6 


3.21 


(7.18) 




4 


6-12 


1.10 


(6.39) 




4 


12-18 


ND 






4 


18-24 


ND 






6 


0-6 


3.94 


(7.11) 




6 


6-12 


ND 






6 


12-18 


ND 






6 


18-24 


ND 






10 


0-6 


3.24 


(6.79) 




10 


6-12 


ND 






10 


. 12-18 


ND 






10 


18-24 


ND 






24 


0-6 


1.60 


(1.88) 




24 


6-12 


ND 






24 


12-18 


ND 






24 


18-24 


ND 






25 


0-6 


1.56 


(2.56) 




25 


6-12 


ND 






25 


12-18 


ND 






25 


18-24 


ND 







*Figures in parentheses indicate RPD, % 



** 



ND, not detected (<1 mg kg"M 



10-12 



In November, 1987 the average was 91%. The first precipitation occurred 
in November. For the months of November, December, January, February, 
March, April and May the rainfall was recorded at 0.84, 2.77, 0.80, 0.54, 
0.11, 1.77 and 0.42", respectively (total = 7.25"). Many of our subplots 
became saturated with water and submerged in some places, particularly on 
the east side of our plot in Pond 4. In January 1988, we collected more 
profile samples to account for effects of the rising water table. We were 
concerned that the rising water would transport the soluble Se within the 
profile to the surface. We noted a considerable amount of Se at the 
6-12" depth in subplots 59, 63 and 65 at this time. The total amount of 
Se in the soil profiles of subplots 59 and 63 increased 1.92- and 4.58-fold, 
respectively. After the wet season a more extensive survey was made in 
July, 1988. The July data indicate that water-soluble Se had been trans- 
ported in the soil profile. There is some question on whether this trans- 
port is an upward or downward gradient or a combination of both. Arguments 
can be made in both cases. The following observations support downward 
movement of Se: 

1. Irrigation will move some soluble Se beyond a 6" depth. 

2. High concentrations (e.g., 10 mg kg"^) of soluble Se are generally 
only observed at the soil surface (Tetsu Tokunaga, LBL, personal communi- 
cation). 

3. Rainfall during the winter season could have leached the water- 
soluble Se to greater depths; however, many of the plots were saturated 
with the rising groundwater. 

4. The addition of organic materials would be expected to promote 
mineralization and solubilization of organic Se. 



10-13 

Arguments in favor of upward noveinent would include: 

1. Careful attention was made not to overwater the plots. The Ap 
horizon was often dry in the late afternoon. 

2. Tensiometer readings throughout the field experiment showed an 
upward gradient of higher tension at the surface during the summer 
months. The readings were more stable at greater depths (6 to 48") 
ranging from 12 to 16 centibars while the shallow depth (0 to 6") 

was of increasing dryness (20 centibars). 

3. Preliminary laboratory studies indicate that a very small frac- 
tion (<2%) of the total Se in the upper 6" is in the water-soluble form 
(unpublished data). A column study was conducted in which 25 g of Pond 9 
sediment were packed into a glass tube and leached with 100 ml of deionized 
water to recover the water-soluble fraction. At zero time 1.5% of the 
total Se (40.7 mg kg~^) was leached and after one month of incubation 
(25°C) a total of 4.1% was recovered. Much of the Se in Pond 4 is tied 

up in the organic fraction which is not readily mobile. To become 
soluble, the bound Se must be mineralized to a mobile species (e.g., 
SeO^"^) to be leached into the soil profile. The cold and wet conditions 
during the winter months would not favor mineralization of organic Se. 
In addition, there is no consistent treatment that favored solubilization 
and eluviation of the Se in the surface layer. 

4. The July and November 1987 data showed very little total Se 
at depths below 6" indicating that there was no leaching during the 
months of August, September, October and November. If leaching was 
responsible for Se movement downward, we would have expected to see 
higher Se levels within the lower profile in the November data. 



10-14 



Some caution is warranted in interpreting the profile data based on 
Se depletion rates because of the high spatial variability of Se at the 
lower depths. Only the upper 6" of soil is being mixed by the roto- 
tiller and homogenizes the soil to allow assessment of dissipation. 
Below the 6" depth, high variability in Se still remains. 

Biological Monitoring 

Attempts have been made to collect biota (mainly insects) from sub- 
plots 52, 54, 55, 56, 57 and 63 and adjacent background areas. Under 
volatilization management, the insects seem to be very scarce. We are 
having extreme difficulty collecting enough samples to be analyzed. 
Frequent rototilling may disrupt the insect habitats and lower their 
population. Attempts are still being made at this time to collect samples 
and when enough biomass is collected, results will be reported. 

Spatial Variability 

Information was obtained to determine the spatial distribution of 
Se in a given area at the Kesterson Reservoir. This study was conducted 
in both Pond 4 and 11 by sampling to a depth of 6". In order to study 
the spatial distribution, an 80- and 150-point grid was established 
overlying the outlines of the experimental subplots. In Pond 4, the 
grid consisted of 3 rows with 5 columns and in Pond 11, 6 rows with 5 
columns (Figs. 10-1 and 10-2). The rows and columns were separated by 








63 





00 00 



^'62 © 








'^ ^64 @ 






54 



© 



10-15 




00 



'9 61 








(209) 56 (0 QO 53 ( 44 





(0 66 (0 



8 1 ^24 J r^s) 




60 




© 




00 00 



7 ) 59 0) 





69 58 35 







1° ) 51 0) 





© 

65 





Fig. 10-1. Schematic representation of soil Se inventory data 
(individual samples) at Pond 4, Kesterson Reservoir. 



10-16 



(^ 




(^ 


(^ 




(^ 


/^^ 




r^ 


r^ 




(T) 


(^ 




(^ 


v^y 




w 


K^J 




vv 


\i/ 




w 


w 




w 


Vi^/ 




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^ 




f^ 


CO 




(^ 


CM 




f^^ 


■^ 




^ 


n 




\^ 






w 






i^ 






w 




(T) 




^ 


(T) 




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r^ 


(T) 




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\zJ 




v^ 


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vv 


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\z^ 






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1 y- 




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(T) 






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(T\ 


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w 




V o y 


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10-17 



8 ft. The soil samples were taken with a soil probe (2" diameter) at 
the end of July, 1987, before the application of soil amendments. All 
samples were sealed in polyethylene bags and stored at 4°C until analyzed. 

The data from Pond 4 (using the 80-point grid) indicated that the 
Se concentrations ranged from a minimum of 10 (subplot 51) to a maximum 
of 209 mg kg"^ soil (subplot 56). In subplot 56 alone, the Se content 
ranged from 39 to 209 mg kg"^ soil indicating high spatial variability. 
The average of the pooled data in Pond 4 was 50.1 mg kg" ^ with a median 
of 39.0 mg kg" . Selenium concentrations at Pond 11 (using the 150-point 
grid) ranged from 1.17 (subplot 27) to 8.63 (subplot 3) mg kg"^ with an 
average of 3.98 mg kg" and a median of 3.75 mg kg"^. Histograms were 
constructed of the frequency of pooled Se levels to show the distribu- 
tion range in Se content at Ponds 4 and 11 (Figs. 10-3 and 10-4). 
The high Se concentrations or "hot spots" are likely to be a result of 
residues from plants which accumulate Se, particularly in the roots. 

Fractile diagrams of Pond 4 and 11 data were constructed assuming 
normal and In normal distribution (Figs. 10-5 to 10-8). This was done 
with individual sample data (as represented in Figs. 10-1 and 10-2) and 
with composite samples (a subset of the individual samples was composited 
by combining even quantities of each of the five soil samples of one sub- 
plot into one composite sample, and then analyzing it for Se). By visu- 
ally comparing the fit between the straight center line and the plotted 
points, i.e., the degree to which theoretical and actual probabilities 
coincide, the statistical distribution of the field data was assessed. 



10-18 



>« 
o 
c 
o 

3 

o 




o 


o 


O 


o 


o 


o 


o 


o 


o 


' 


(N 


m 


■* 


m 


(O 


r«. 


00 


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»- cvj 



<£> 



oooooooooooo 
o»-c\jn'rir)tDr^00O)O'- 

— — ^ — ^•.- — .^^^CVJCVJ 
0>0'-C\JCO'^m«3r--QOO>0 



Se {mg/kg soil) 



F1g. 10-3. Frequency distribution of soil Se Inventory 

data (individual samples) at Pond 4, Kesterson 
Reservoir 



10-19 



Q 

C 
0) 

3 

a 




o 


o 

o 


o 
in 


o 
o 


o 
m 


o 
o 


o 
m 


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o 


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in 


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o 


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en 


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1 


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o 


tn 


o 


in 


o 


in 


o 


In 


o 


in 


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in 


o 


m 


o 


in 


o 


in 




o 


_ 


^ 


CM 


CM 


CO 


CO 


^ 


T 


m 


in 


(O 


CO 


r«. 


r^ 


00 


00 



Se {mg/kg soil} 



Fig. 10-4. Frequency distribution of soil Se inventory data 

(individual samples) at Pond 11, Kesterson Reservoir. 



10-20 



For the individual inventory samples, a In normal distribution was evi- 
dent. A In transformation of the data produced a much improved fit, in 
particular with Pond 4 samples (Figs. 10-5 and 10-6). However, composit- 
ing the soil samples and assuming normal distribution also resulted in 
slight improvements (Figs. 10-5 through 10-8). More pronounced was the 
shift towards normal distribution with time. In November, the individual 
sample data displayed a very close fit, and In transformation did not 
improve that situation significantly (Figs. 10-7 and 10-8). Comparing 
the fractile diagrams of Pond 4 individual In transformed inventory data 
(Fig. 10-5) with Pond 4 individual non-transformed November data (Fig. 
10-7) shows how after 90 days of the experiment, the untransformed data 
displayed almost the same close fit as the In transformed inventory data. 

We interpret these observations in the following way. Originally, 
Kesterson soil Se data were In normal distributed, but with time 
normal distribution was approached through the mixing action of the 
rototiller. In practical terms. In normal distribution of soil 
Se data implies that most values are below the mean and a few values 
greatly exceed the mean, i.e., reflect "hot spots". The statistical 
observations support that rototilling removes "hot spots" by spreading 
out the high concentrations. 

Comparing the means and standard deviations of the soil data (Table 
10-6) show the same trend: after 3 months of soil management, the 
standard deviations were reduced by roughly 50% in Pond 4 and Pond 11, 
while the means did not change significantly. 



Individual Samples 
assuming normal distribution 



Composite Samples 
assuming normal distribution 



10-21 



1.0' 



0.8- 



0.6- 



0.4- 




0.2 - 0i 



0.0 I ■ ■ I ' ■ I ■ ' I ■ ■ I ■ ' 
0.0 0.2 0.4 0.6 0.8 1.0 



PsO) 



Individual Samples 

assuming In normal distribution 




0.0 f I ' I ■ ■ I ■ ' I ' ' I I 

0.0 0.2 0.4 0.6 0.8 1.0 




0.0 0.2 0.4 0.6 0.8 1.0 

PsG) 

Composite Samples 
assuming in normal distribution 



1.0- 






/ 


• 






♦ / 


0.8- 






/ 


■ 






/ 


3).6- 

a! 




/ ♦ 








/ ♦ 




0.4- 












/ ♦ 








X * * 




0.2 J 








0.0- 


/ 


/• ♦ 





Ps(j) 



0.0 0.2 0.4 0.6 0.8 1.0 

Ps(j) 



Fig. 10-5. Fractile diagrams for soil Se inventory data for 

individual and composite samples at Pond 4, Kesterson 
Reservoir. 



Individual Samples 
asssuming normal distribution 



1.0 



0.6- 



0.2- 




Composite Samples -i | 

assuming normal distribution 




Ps(j) 



PsO) 



Individual Samples 

assuming In normal distribution 




0-0 f ' ' I I 

0.0 0.2 0.4 0.6 0.8 1.0 

psa) 



Composite Samples 
assuming In normal distribution 




Q-..4- 



00 I I I I I I I ,, 

0.0 0.2 0.4 0.6 0.8 1.0 

PsO) 



Fig. 10-6. Fractile diagrams for soil Se inventory data for 

individual and composite samples at Pond 11, <esterson 
Reservoir. 



Individual Samples 
assuming normal distribution 



Composite Samples 
assuming normal distribution 



10-23 




1.0' 



0.0 f » ^ I ' 'I ' ' '""1 ™i ■ I I * 
0.0 0.2 0.4 0.6 0.8 1.0 



PsG) 



Individual Samples 

assuming in normal distribution 




0.0 I I I I I I I I I I I I I I I 

0.0 0.2 0.4 0.6 0.8 1.0 



PsO) 



Composite Samples 
assuming in normal distribution 



i.u- 






y 








V 


0.8- 






/ 






y 




0.6- 




/ 




^ 




/* 




^_ 




/ 




a-J.4- 


/ 


r 




0.2- 


♦ / 






0.0- 


1 1 1 1 1 







0.0 0.2 0.4 0.6 0.8 1.0 



1.U- 












/ 


0.8- 










y 


/ 


3).6- 










♦ / 




L 










♦ / 














♦ X 




0.4- 








/ 


/ 












/ 












/ 


♦ 






0.2- 




■/ 


/• 








0.0- 


i 













PsO) 



0.0 0.2 0.4 0.6 0.8 1.0 

PsO) 



Fig. 10-7. Fractile diagrams of soil Se November (1987) data for 
individual and composite samples at Pond 4, Kesterson 
Reservoir. 



Individual Samples 
assuming normal distribution 



Composite Samples 
assuming normal distribution 



10 




0.0 0.2 0.4 0.6 0.8 1.0 



PsO) 



Individual Samples 

assuming in normal distribution 





Ps(i) 

Composite Samples 

assuming In normal distribution 



i.u - 










/ 












/ 


0.8- 












,^«. 1 








/ 




31.6- 








/ 




— 






/ 






Q. 






/•• 






0.4- 




/ 


r 






02- 


/ 


(^ 








0.0 -■ 


/•• 











0.0 0.2 0.4 0.6 0.8 1.0 



PsO) 



PsG) 



Fig. 10-8. Fractlle diagrams of soil Se November (1987) data for 
individual and composite samples at Pond 11, Kesterson 
Reservoir. 



10-25 



Table 10-6. Means (u) and standard deviations (S) of individual 
soil sample data (tng Se kg"^ soil). 





Pond 


4 


Pond 


11 


Statistic 


Inventory 


November 


Inventory 


November 


u 
S 


50.99 
32.71 


42.66 
17.03 


4.01 
1.23 


4.26 
0.67 



10-26 



This information reveals that the proposed soil treatment technique 
to mitigate Se contamination at Kesterson Reservoir constitutes a two- 
pronged approach. One aspect is the physical effect of the rototilling, 
which can be considered a "treatment" by itself, in that it removes "hot 
spots", i.e., dangerously high Se levels. The other aspect is the decay 
of the mean Se level through microbiological action. 

For the statistical treatment of the data, it was decided to assume 
normal distribution for all soil Se values from both ponds. The follow- 
ing reasons supported that decision: 

1. Since the data trend towards normal distribution with time, 
consistency in assumptions is provided by assuming normal distribution 
from the beginning. 

2. According to the central limit theorem, averaging In normal 
distributed data causes them to approach normal distribution. Averaging 
of the data was performed at two levels: i) soil samples were composited 
throughout the experiment, except for the spatial variability study, 

and ii) results were averaged between subplots with the same treatment. 
The observed improvement of fit in the fractile diagrams (Figs. 10-5 
to 10-8) through compositing the samples confirms the validity of the 
central limit theorem for Kesterson soil Se data. 

3. By definition, the mean in a normal distribution remains the 
same when the spatial variability (or s^) is reduced through roto- 
tilling. In other words, the mixing effect will make the soil Se 
values converge towards their true mean. Reductions in the mean can 
then be attributed to loss of Se from the soil due to microbial ly 
mediated volatilization. 



10-27 



Soil Selenium Removal from the Ap Horizon 

Soil samples were collected on a monthly basis when weather per- 
mitted, typically during the first week of the month. In January, 1988 
Pond 4 was saturated and many of our subplots (e.g., 55 and 64) were 
under water. Pond 11 was also wery wet. These conditions prevented us 
from taking soil or gas samples at that time. It was not until 
January 14-19, 1988 when the field was beginning to dry out and we were 
able to obtain soil samples. Because it was so late into January, we 
decided to take the next soil samples during the first week of March. 
Thus there are no February soil data. In each subplot, subsamples were 
taken in a 5-point pattern (see page 10-1). Subsamples within each 
subplot were composited to account for the spatial variability. 

Since the soil Se concentrations varied considerably between the 
individual replicates (subplots) of each treatment, the data had to be 
scaled using the initial (September) values of each individual subplot. 
The soil Se values from each subplot were expressed in percent of the 
initial value, pooled, and plotted and analyzed together. Graphs and 
statistics for individual subplots are shown in addition. The best 
value by which to scale the data was chosen from two options: the 
measured initial value, or the calculated value obtained as the inter- 
cept of the regression line with the y-axis (zero time). Using Pond 4 
data, both methods were performed for comparison. Correlation coeffi- 
cients (r) for the regression of scaled and pooled soil Se data versus 



10-28 



time were calculated. Table 10-7 shows that overall the higher 
r-values were obtained by using the y-intercept. Therefore, this 
method was used consistently throughout this study. 

The scaled and pooled data from the same treatments were subjected 
to a regression analysis. The data seemed to best fit a linear rela- 
tionship of the initial rates of a first-order decay during this 10-month 
field study vs. polynomial, logarithmic and exponential. The number of 
data points per treatment ranged from 10 to 44. 

Pond 4 

Figures 10-9 to 10-15 show the relationship between each of the 
treatments in Pond 4 and the depletion in soil Se content in the Ap 
horizon with time. These figures show the dispersion in the collected 
data and provide the Se removal rates within the linear regression 
equations. Table 10-8 consists of a summary of the soil Se removal rates 
and indicates how well the linear regression analysis fits the data. The 
following treatments show soil Se removal (% per month) ranked in the 
following order: molasses (4.46) > citrus + Zn + N (2.77) >_ cattail 
(2.69) >_ moist (2.58) > citrus (2.14) > straw (1.49) > manure (1.19). 
In terms of fit with the linear regression analysis, the following 
treatments were significant at the i) 99.9% level (moist and citrus), 
ii) 99% level (citrus + Zn + N), and iii) 95% level (molasses and straw). 
The cattail (r = 0.545) and manure (r = 0.344) treatments were not 
significant in this analysis. 



10-29 



Table 10-7. Coefficients of determination for regression of 
pooled soil Se data versus time. 



Scaled by: 



Initial 
Treatment (Pond 4) Non-scaled measurement y-intercept 



Moist .303 .269 .424 



Manure .026 .082 .118 



Straw .039 .284 .158 



Citrus .159 .356 .385 



Citrus + Zn + N .288 .423 .413 



10-3C 



130 





Sap 1.87 



4 6 

Month 



1 
Jul 1,88 



Subplot 56 

y = 81 .302 . Z5687X r=.822 




4 6 

Month 



8 10 



Subplot 57 

y . 58.936 - 0.89233X r..429 



Subplot 62 



ou - 








70- 


• 






60- 


1 


• * 


• 


50- 






• 


40- 


• 




1 



2 4 6 8 10 

Month 



y « 64.323 - 1.9809X r=.769 
80 




40 I < I > I ' I < I 

2 4 6 8 10 

Month 



Fig. 10-9. Soil selenium removal rates in response to added moisture 
to Pond 4, Kesterson Reservoir. 



10-31 



130 



120 - 



110 - 



80- 



70- 



60 




Sep 1,87 



y— 1 .49x + 100.386, r=.398* 




-r 
2 



Month 



10 
Jul1,88 



Subplot 59 

y - 32.039 - 0.20366X r«.292 




2 4 6 8 10 

Month 



Subplot 55 

y - 73.067 - 1 .3902X r».593 




50 I ' I I I ' I ■ I 

2 4 6 8 10 
Month 



Subplot 52 

y -55.218 - 1.4756X r=.654 



ou - 


• 








• 


• 




SC- 




N 


L 


AD - 

30- 


' r • I • 


— T— 


• 
• 

' I ' 



2 4 6 8 10 
Month 



Fig. 10-10. Soil selenium removal rates in response to barley straw 
to Pond 4, Kesterson Reservoir. 



10-32 




Month 



Subplot 60 

y = 34.685 -0.2921 Ox r=.41 1 




28 1 > I I I I I ' I 

2 4 6 8 10 
Month 



Subplot 53 

y =49.817- 1.1 280x r=.567 




30 I ' I ■ I ■ — I ' I 

2 4 6 8 10 

Month 



Subplot 51 

y = 21.521 -9.7185e-2x r=.134 




2 4 6 8 10 
Month 



Fig. 10-11. Soil selenium removal rates in response to cattle manure 
to Pond 4, Kesterson Reservoir. 



10-33 



120 



110 - 



TO- 



GO 




Sep 1,87 



y = 100.00 -2.1 400x r=.621' 



t 



Month 




10 
Jul 1,88 



Subplot 54 

y = 38.065- 1.21 68x r=.817 
50 




' I ' I ' 1 ' I 

2 4 6 8 10 
Month 



Subplot 58 

y = 34.964 - 0.40476X r=.415 



^u - 




• 


38- 






36- 






34- 


^v^ 




32- 




\. 


• 


• 


• • ^ 


30- 




• 


28 - 




1 



Subplot 61 

y = 50.241 - 1.0378X r=.742 
60 




2 4 6 8 10 

Month 



2 4 6 8 10 
Month 



Fig. 10-12. Soil selenium removal rates in response to citrus pulp to 
Pond 4, Kesterson Reservoir. 



10-3> 



140 





Sep 1,87 



4 6 

Month 



10 
Jul 1.88 



Subplot 63 

y > 68.736 - 2.2409X r..795 



o 

M 

® 

CO 
o 

E 



BU - 








TO- 


s^ 


• 




GO - 


• • 


\ 




50- 








40- 






• ^ 



Subplot 64 

y -50.734- 1.1 532x r=.520 




2 4 6 8 10 

Month 



2 4 6 8 10 

Month 



Fig. 10-13. Soil selenium removal rates in response to citrus + Zn + 
N to Pond 4, Kesterson Reservoir. 



10-35 




Month 



Fig. 10-14. Soil selenium removal rates in response to molasses to 
Pond 4, <esterson Reservoir. 



o 

(0 

CO 

E 





Sep 1,87 



4 6 

Month 



Fig. 10-15. Soil selenium removal rates in response to cattail straw 
to Pond 4, Kesterson Reservoir. 



10-37 



Table 10-8. Soil selenium removal rates in response to specific 
amendments added to Pond 4, Kesterson Reservoir. 



Treatment 


% 


loss mo 


inth"^ 


r 


(numbe 


N 

r of samples) 


Moist only 




2.58 




0.65*** 




30 


Straw + N 




1.49 




0.40* 




27 


Citrus 




2.14 




0.62*** 




30 


Manure 




1.19 




0.34 




30 


Citrus + Zn + N 




2.77 




0.64** 




20 


Molasses 




4.46 




0.76* 




10 


Cattail 




2.69 




0.55 




10 



*, **, *** indicate significance at the 95, 99 and 99.9% level, 
respectively. 



10-38 



With the exception of the molasses and cattail treatments, the soil 
removal data confirm the volatile emissions data. The addition of 
citrus + Zn + N was an effective treatment for both Se soil removal 
and volatilization, while citrus and moist-only were intermediate 
and straw and manure were the least effective. Although the cattail 
and molasses treatments gave fairly high soil Se depletion rates, some 
caution should be used in interpretation of these treatments since the 
regression was based on only 10 data points. 

There was no evidence of a dilution effect as a result of continual 
addition of mass (i.e., amendments) since the moist-only subplots showed 
comparable Se removal rates. 

Pond 11 

Figures 10-16 to 10-25 illustrate the soil Se removal rates in 
response to each treatment in Pond 11. Table 10-9 expresses this removal 
rate on a monthly basis with corresponding r values for each linear 
regression analysis. The moist-only treatment showed a considerable 
drop in Se content (22%) over a 10-month period. This linear decrease 
was highly significant at the 99.9% level. Straw added along with N 
(C/N varying from 5 to 20) also produced a substantial reduction with 
an average monthly Se loss of from 1.47 to 2.29% per month. Other 
treatments that promoted Se loss included manure (62, 89 t/ac), citrus 
pulp (14 t/ac), citrus + N and citrus + Zn + N. All other amendments 
had little effect on soil Se removal. The extreme loading rates of 



10-39 



o 

c 



14U - 


► 




y 


= 100.00 


- 2.2229X 


r= 


.508*" 








120- 
























• 
• 


s 




• 












• 


100 - 


• 


• 




t 










• 






> 








...^____^ 




• 


• 




• ; 




> 


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• 


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• 


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■ 




• 


• 








• 


• 


• 


• 


• 

• 


• 


• 


60- 














• 






( 


40- 










• 













1 

Sap 1.87 



4 5 6 

Month 



10 11 

Aug 1 , 88 



y - 4.9394 - 9.3227e-2x r-.672 




I < I ■ I ■ I ■ I 
) 2 4 6 8 10 

Month 

y = 6.1995- 0.281 70x r=.797 



o - 


1 






7 - 








IJOS 


, • 




Subplot 12 


0.6- 








1 ■ 




> 


■v,.^^^ 


W 5- 






• ^*^*x^ 


o> i 






^N,,^^ 


^4. 






• r'^* 


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2 


4 6 8 10 

Month 



no^ 


- 4.4058 - 2.6570e-2x r=..210 


o 


• 


• 

• * Subplot? 


o 







t^l.O- 

E 


1 


■ j^ 

• 


3.5- 




• • 



2 4 6 8 10 

Month 

y = 5.1 794 - 9.61 52e-2x r=.656 



Subplot 30 




3 I > I ■ I ■ I 



I ' r 



2 4 6 8 10 

Month 



Fig. 10-16. Soil selenium removal rates in response to moisture to 
Pond 11, Kesterson Reservoir. 



10-4C 



tn 



120 



110 



100 - 



O 90- 



80 - 



70 



y = 101.60 -1.4332X r=.525* 



I I I 

12 3 

Sep 1,87 



I I I 1 I I I 

4 5 6 7 8 9 10 11 

Month Aug 1.88 



Subplot 27 

y - 2.8878 - 6.0087e-2x r=.257 




Subplot 14 

y - 3.9988 -6.791 7e-2x r=.593 




-1—1 — 1 — I — I— I— I — I — > — r 

2 4 6 8 10 
Month 



Fig. 10-17. Soil selenium removal rates in response to barley straw 
to Pond 11, Kesterson Reservoir. 



10-41 



d> 
CO 

*c 



120 



110 



100 



90- 



80- 



70 






y - 99.996 - 1 .2559x r-.382' 






Month 



I I ■ I I I I I 1 r 

1 2 3 4 5 6 7 8 9 1011 

Sap 1,87 



Aug 1 , 88 



Subplot 1 

y . 4.8871 - 7.5252e-2x r..392 




3 I ' I ' I ' I ' I ' I 
2 4 6 8 10 

Month 



Subplot 3 

y. 5.4808- 5.21 83e-2x r..292 




4 I ■ I ■ I — ' I ' I — f— r 
2 4 6 8 10 

Month 



Subplot 10 

y -4.0146 -5.1 221 e-2x r=.524 



4.2- 


• 


• 






■ 








• 


4.0- 


N 








3.8- 


) 


K 


\ 


• 


3.6- 










3.4- 










3.2- 






• 


• 






1 ' 


T ' 


1 ' I ' 1 





2 


4 


6 8 10 








Month 



Fig. 10-18. Soil selenium removal rates in response to cattle manure 
to Pond 11, Kesterson Reservoir. 



lO-42( 



120 




1 

Sep 1.87 



■< — 1 1 — 1 — r 

3 4 5 6 7 

Month 



T- 1 1 

8 9 10 11 

Aug 1,81^1 



Subplot 4 

y =. 5.4065 - 2.8480G-2X r».219 
6 



o 



5- 



w 

E 




Subplot 8 

y - 5.9969 - 6.7734e-2x r-.485 
7 




( 



Subplot 1 1 i 

y - 4.0988 -t- 7.8656e-3x r».0! 
4.6" 



4.4- 



4.2 



4.0- 



3.8- 



3.6- 



3.4 



Month 



Month 



■ I ■ I I I I I I I 

2 4 6 8 10 

Month 



Fig. 10-19. Soil selenium removal rates in response to citrus to 
Pond 11, Kesterson Reservoir. 



10-43 



0) 
(0 

a 

c 



120 



110- 



100 



SO- 



TO 



y = 99.997 - 2.2534x r=.771 ' 



1 I 1 I I I 1 I 1 I 

1 2 3 4 S 6 7 8 91011 

Sep 1.87 



Month 



Aug 1, 88 



Subplot 21 

y. 4.5981 -0.1 0308X r-.817 



o 

CO 

O) 

£ 




SuDplOt 28 

y.4.5176-0.10233x r-.733 




I ' I ' I ■ I ' I 

2 4 6 8 10 

Month 



Fig. 10-20. Soil selenium removal rates in response to barley straw 
(C/N = 5) to Pond 11, Kesterson Reservoir. 



10-44 



o 
CO 



120 



110- 



100 



80 - 



70- 



60 



1 

Sep 1,87 



T- 
2 



y- 100.00 -2.2942X r=.58' 



T" 
4 



T 1 -P 



5 6 7 

Month 



§ • 



— r- 
10 



1 1 
Aug 1 , 88 



SubDiot 2 

y - 7.2278 - 0.22372X r-.644 
9 




' I ' I ' I I I ' I 
2 4 6 8 10 

Month 



Subplot 9 

y = 5.1223 -8.9390e-2x r=.620 
6 



5 - 




2 4 6 8 10 

Month 



Subplot 5 

y = 5.0520 -0.1 031 7x r=.550 




' I ' I ■ I I I I I 



2 4 6 8 10 
Month 



Fig. 10-21. Soil selenium removal rates in response to barley straw 
(C/N = 10) to Pond 11, Kesterson Reservoir. 



10-45 



O 

c 



120 



110- 



100 



» • 



90- 



80- 



70 

Sep 1.87 



y = 99.993 - 1 .4726x r=.595* 



Month 



-I 1 1 1 1 I 1 1 1 I 

1 2 3 4 5 6 7 8 9 1011 



Aug 1,88 



Subplot 29 

y.4.1956-S.9868e-2x r..606 



o 
(/) 

o> 

« 
CO 

E 



4 -I •^'^"*->*^ 

3 ■ I ■ I ■ I ■ I ' I 



4 6 8 10 
Month 



Subplot 17 

y « 3.5058 - 5.3237e-2x r=.587 



4.0- 
















• 








3.5- 


K 


















^^ • 


• 


3.0- 








^^^ 


■-^^ 








• 






2.5- 








1 * 1 


■ — 1 — 1 



2 4 6 8 10 

Month 



Fig. 10-22. Soil selenium removal rates in response to barley straw 
(C/N = 20) to Pond 11, Kesterson Reservoir. 



y - 2.8327 - 4.7123e-3x r-.066 



3.4 



3.2- 



CO 




O) 



2.6- 



2.4- 



2.2 



41 t/ac 



I — r— I — I — I — I — I — I — I— r 
123 45 67 8 91011 
Sep 1.87 



Month 



Aug 1,88 



O 
(0 

o 
en 

E 



y - 3.5667 - 7.3073e-2x r=.653' 




12 3 4 5 6 7 8 9 1011 
S«P1.87 Aug 1,8 

Month 



3.4 



y - Z8161 - 1.42590-2X r-.247 



O 
(0 

E 



3.2- 



3.0 



2.8- 



2.6- 



2.4 

1 
Sep 1,87 



137 t/ac 



"> — I — I — I — I — I — I — r 
234 56 789 1011 



Month 



Aug 1 , 88 



y - 2.8090 + 6.6027e-2x r..688* 




01 2345 67891011 

^P'-^^ Month Aug 1.1 



Fig. 10-23. Soil selenium removal rates in response to varying 

application rates of cattle manure (41, 62, 137 and 206 
t/ac) to Pond 11, Kesterson Reservoir. 



10-47 



y - 4.0674 - 2.3282e-2x r..38 



4.4' 



4.2- 



3.6- 



3.4 




9 Vac 



-1 — I — I — I — I I I I I — r- 
2 4 6 8 10 



Sep 1,87 



Month 



Aug 1,88 



O 
(0 

0) 
0) 

E 



y - 4.0859 - 9.0006e-2x r=,699* 


■» 


4 - 


^>v,^^ • 




• "^^ 


, 


• *^-^ • 




^^^« 
•\^ 


3- 






• 


2- 


I4t/ac 

■ 1 — ■ 1 ■ 1 ' — 1 — < — 1 — 



2 

Sep 1,87 



Month 



8 10 

Aug 1 , 88 



y - 3. 1 072 - Z0797O-2X r-.281 




y « Z9422 + 6.2366e-2x r».596 



O 
(A 

(/) 

E 




Month 



2 

Sep 1,87 



4 6 3 

Month A'^^ss 



Fig. 10-24. Soil selenium removal rates in response to varying 

application rates of citrus pulp (9, 14, 20 and 45 t/ac) 
to Pond 11, Kesterson Reservoir. 



10-48 






4.0 



3.8- 



O 3.6- 
(0 



3.4- 



0> 32- 

E 



3.0- 



2.8 



y ■ 3.3028 + 5.3552e-3x r-.071 
Citrus +2n 



• • 



I I I I 



4.8 



1234 56 78 91011 
Sep1,87 Aug1,88 

Month 



y-4.2175-4.5902e-2x r=.535 
Citrus -f N 




Month 



4.2 



4.0 



o 

M 
O) 

CO 

E 



3.8- 



3.6- 



3.4- 



y - 3.7563 ■ 3.7220e-2x r- 
Citrus -f Zn +N 



.555 



3.2 

1 
Sep 1,87 



4 5 



7 8 



Month 



I I 

9 10 11 
Aug 1 , 88 



Fig. 10-25. 



Soil selenium removal rates in response to citrus + Zn, 
citrus + N and citrus + Zn + N to Pond 11, Kesterson 
Reservoir. 



10-49 



Table 10-9. Soil 


selenium removal rat 


es in res 


ponse 


to specific 


amendments added 


to Pond 


11, Kesterson 


Reservoir. 


Treatment 


% loss month"-^ 


r 


N 
(number of samples) 


Moist only 


2.22 




0.51*** 




44 


Straw (no N) 


1.43 




0.53* 




22 


Manure (89 t/ac) 


1.26 




0.38** 




33 


Citrus (30 t/ac) 


0.49 




0.20 




33 


Straw (C/N = 5) 


2.25 




0.77*** 




22 


Straw (C/N = 10) 


2.29 




0.58** 




27 


Straw (C/N = 20) 


1.47 




0.60** 




22 


Manure (41 t/ac) 


0.17 




0.07 






Manure (62 t/ac) 


2.05 




0.65* 






Manure (137 t/ac) 


0.50 




0.25 






Manure (206 t/ac) 


+2.35 


(gain) 


0.69* 






Citrus (9 t/ac) 


0.57 




0.38 






Citrus (14 t/ac) 


2.20 




0.67* 






Citrus (20 t/ac) 


0.68 




0.28 






Citrus (45 t/ac) 


+2.11 


(gain) 


0.60 






Citrus + Zn 


+0.18 


(gain) 


0.07 






Citrus + N 


1.09 




0.54 






Citrus + Zn + N 


0.99 




0.56 







**, *** indicates significance at the 95, 99 and 99.9% level, 
respectively. 



10-50 

manure (206 t/ac) and citrus (45 t/ac) actually showed a gain in Se 
content over time. Since casein was applied so late in the experiment, 
there is no soil Se removal data for this particular treatment. 

The soil Se depletion data indicates that there is considerable 
dissipation of Se from the Ap horizon. This diminishing Se level could 
partially be attributed to other factors in addition to volatilization. 
For example, rototilling to the 6" depth will inevitably cut and mix 
deeper and shallower in some of the subplots. This variation in depth 
after repeated rototilling may move the Se content initially at 0-6" 
a few inches deeper, possibly diluting the Se in the Ap horizon. In 
addition, irrigation could have leached some of the soluble Se into the 
greater soil depths. However, if leaching was a contributing factor, 
this was not evident until the wet season of the winter months (January, 
1988). Although Figures 10-9 to 10-25 show a steady decline in Se content 
in the Ap horizon throughout the 10-month sampling period, attempts were 
not made to calculate mass balances. Nevertheless, volatilization is 
active in the field and is certainly dissipating the Se inventory from 
the Ap horizon. Further work is continuing in determination of the fate 
of the Se inventory. 

Statistical Relationships 

A correlation matrix was constructed to determine the relationship 
between the soil Se depletion data, gas emission, soil temperature (°C) 
and time (months) (Tables 10-10 and 10-11). In Pond 4 there was a strong 
correlation between the soil temperature and Se gas emissions data 



10-51 



Table 10-10. Correlation matrix (r values) between soil Se depletion, 
gas emission, soil temperature, and time in Pond 4. 



Variables 


n 
(obser- 
vations) 


Soil 
Se 


Se gas 


Soil 
temperature 
(°C) 


Time 
(months) 


Soil Se 


161 


1 


0.212 


-0.154 


-0.172 


Se gas emission 


576 




1 


0.433 


0.217 


Soil tempera- 
ture (°C) 


416 






1 


0.739 


Time (months) 


576 








1 



10-52 



Table 10-11. Correlation matrix (r values) between soil Se depletion, 
gas emission, soil temperature, and time in Pond 11. 



Variables 


n 
(obser- 
vations) 


Soil 
Se 


Se gas 


Soil 

temperature 

(°C) 


Time 
(months) 


Soil Se 


329 


1 


0.108 


0.110 


-0.074 


Se gas emission 


868 




1 


0.257 


0.074 


Soil tempera- 
ture (°C) 


781 






1 


0.745 


Time (months) 


900 








1 



10-53 



(r = 0.433**, n = 416). In addition, there was a relationship between 
gas emission and soil depletion (r = 0.212*. n = 161). As the soil 
inventory decreased, the gas emission decreased with time supporting 
a first-order reaction. In Pond 11, the only significant relation- 
ship was the gas emission data and soil temperature (°C) (r = 0.257**, 
n = 781). 

Results from the San Luis Drain sediment experiment will indicate 
the effectiveness of the inverted chamber used to monitor the emission 
of gaseous Se in the field compared to the soil Se depletion rates since 
Se cannot be lost through leaching. 



11-1 



CHAPTER 11 
VOLATILIZATION AS A BIORECLAMATION PROGRAM 

Factors Affecting Volatilization 

Factors which promoted volatilization in the field included a 
carbon source, aeration, moisture, high temperatures and specific acti- 
vators (e.g., Zn and Co). Disking in the native vegetation has been 
shown to promote volatilization as long as the soil Is kept moist. 
The vegetation provides a carbon source allowing the methylating organ- 
isms to proliferate and take up soluble Se within their surrounding 
environment. As a means of detoxification, the Se is methylated and 
released into an innocuous gaseous form into the atmosphere. 

Frequent tillage must be practiced to allow well aerated conditions. 
Microbial volatilization depends upon an oxygen supply since the predomi- 
nant soil microbial population responsible for volatilization consists 
of aerobic fungi. Good soil porosity is also necessary to facilitate 
diffusion of the alkylselenlde gas. Tillage is necessary to break any 
crust that may form as a result of the sprinkler irrigation, preventing 
the gas to readily escape. Deep plowing may be required for the buried 
seleniferous sediment as a result of filling of the ephemeral pool areas. 

The soil should be allowed to go through wetting and drying cycles 
to release the organically-bound Se. Drying the soil with subsequent 
rewetting has long been known to create a burst of carbon dioxide pro- 
duction compared with a soil maintained in a field-moist condition 



11-2 



(Birch, 1959; Stevenson, 1972; Jager and Bruins, 1975). This has been 
attributed to a breakdown of and an increase in solubility of the soil 
organic matter. Much of the Se is tied up in the organic fraction of 
the seleniferous soil at Kesterson Reservoir (particularly the southern 
ponds) (unpublished). Wetting and drying will enhance the quantity of 
Se that is released through mineralization and made available for uptake 
by the methyl ating organisms. The summer months should provide the 
optimum conditions for volatilization during irrigation. The soluble Se 
content should increase as the soil dries out between irrigation cycles. 
Also, allowing the soil to dry out will enhance the dissipation of DMSe 
into the atmosphere. 

Volatilization is highly dependent on temperature. Daily and 
seasonal variations indicated that greater quantities of alkyl selenides 
are produced during the warmer temperatures. The summer months showed 
the greatest gas emission rates. 

The addition of Zn was shown to stimulate volatilization in the 
laboratory, greenhouse and field studies. The geometric mean of Zn con- 
centration in U.S. soils is 44 mg kg"^ but usually ranges from 10 to 
300 mg kg"^. Zinc deficiencies in plants occur when Zn concentrations 
are less than 25 mg kg"^. Much of the soil Zn is adsorbed to organic 
matter and immobilized, particularly in calcareous soils. Zinc could 
be added as a micronutrient to stimulate microbial volatilization of Se. 

If volatilization were to be used as a bioremedial plan to remove Se 
in conjunction with other treatment techniques, several parameters would 
have to be assessed including: type of irrigation equipment, quality of 
water, available C sources and cost of equipment and amendments. 



11-3 



Irrigation Equipment 

The irrigation equipment should consist of aluminum pipeline with 
24" risers. This would be a solid set system for 1280 acres. Irriga- 
tion wheel lines might also be considered in light of the necessity for 
periodic tilling and/or amendment addition. The booster pumps (1800 
to 2200 gpm) would be placed near the water source. The water should 
be applied just to wet the upper surface soil. If too much water is 
appied, the soluble Se may be mobilized out of the surface layer making 
it unavailable for volatilization. 

Quality of Water 

Preliminary tests on volatilization of Se with Pond 4 soil 
(Kesterson Reservoir) were made with Fremont Canal water (0.7 dS m" ^) , 
well water (7.5 dS m" ) which is currently being used in the filling 
operation of ephemeral pool areas, and deionized water. Table 11-1 
indicates the elemental composition of the field water samples. There 
was no significant difference in volatilization of Se among the three 
sources of water when applied to soil under short-term (120-h) incuba- 
tion. Although the highly saline well water has a very high boron (B) 
content (3.87 mg L'^), this element has little effect on microbial vola- 
tilization of Se (Karlson and Frankenberger, 1988b) The added salts are 
expected to have a minimal influence on the already saline Kesterson 
soil (Pond 4, 22 dS m"^; but further work is needed to determine the 
long-term effect. 



11-4 



Table 11-1. Quality of water used for volatilization of selenium. 



Composition 


Fremont Canal 


water 


Well water 






mn 1 ~ ^-. 








■ ~ ~ ~ — Ijiy L^ — 




NH4+-N 


0.61 




0.25 


NO3--N 


1.89 




1.15 


Ca 


38 




303 


Mg 


21 




122 


Na 


111 




1300 


Si 


9.2 




13 


B 


0.47 




3.87 


Ba 


0.053 




0.037 


Sr 


0.453 




2.91 


Li 


ND* 




0.21 


AT 


0.848 




ND 


Fe 


0.411 




1.48 


Mn 


— 




4.58 


Mo 


0.003 




0.013 



*ND, not detectable 



11-5 



Available Carbon Sources 

The volatilization field study indicates that the addition of 
citrus + Zn + N and proteins (particularly casein) dramatically enhanced 
methyl ati on of Se. Recent data from the San Luis Drain experiment indi- 
cate a 5.63-fold enhancement in Se volatilization with cottonseed meal 
(41% protein) over the moist-only treatment (10/7/88). Unfortunately, 
our discovery that protein amendments are superior among all other 
treatments is a recent one and thus we have no soil Se depletion data 
as of yet. Other proteins being tested to enhance volatilization include 
soybean meal and saf flower meal. It is evident that the addition of N 
does not enhance volatilization of Se in the southern ponds. There is 
some indication that the emission rates of volatile Se from the citrus + 
Zn + N treatment may even be greater if N were omitted. 

Cost of Equipment and Amendments 

Moisture appears to be the major limiting factor in this bioremedi- 
ation process, particularly in the summer months. Irrigation equipment 
quoted by Water-Ways (San Joaquin, CA) would cost approximately $425,000 
to $761,000 including all pipes and pumps (see Appendix D for details). 
The tillage operation is estimated at $500,000 per year. Attempts 
should be made to disk the soil every other week during the warm summer 
months. 

Inquiries were made to business establishments that could pro- 
vide some of the more promising amendments to be incorporated into the 



11-6 



seleniferous soil. The source, availability and cost of the bioamend- 
nents are listed in Table 11-2. 

The major expense for citrus pulp (orange peel) would be transport. 
The wet tonnage would cost approximately $10/ton plus freight (total, 
$21/ton). Cattle manure was demonstrated to promote methyl ation of Se 
in Pond 11. The quoted price from Harris Ranch is $20/ton. The protein 
materials (cottonseed meal and soybean meal) retail for approximately 
$250 and $280/ton, respectively. 

Many of these carbonaceous materials could be applied with a 
spreader truck or a drag scraper. On a long term basis, the addition 
of C sources would not only promote the Se biomethylation reaction as a 
remedial process to remove Se, but also promote the fertility of the 
treated soil at Kesterson Reservoir. Incorporation of these materials 
would lead to greater buffering capacity, cation exchange capacity, 
nutrients for plant growth, microbial diversity, water holding capacity, 
and granulation (soil structure), overall promoting this site to a very 
rich agronomic environment. 

Considering the cost of tillage and irrigation alone this bio- 
reclamation program would cost approximately $1 - $1.5 million per year. 
If it is found that citrus + Zn (southern ponds) or a source of protein 
enhances Se removal considerably more than moisture alone, the addi- 
tional cost would break down as follows: with 2 applications per year 
(IX spring [April] and IX summer [July]), the citrus at 50 t wet 



11-7 



Table 11-2. Costs of amendments for Se volatilization as a 
bioremediation program. 



Source 


Material 


Available 


Costs 


CCP1 


citrus peel 


year 
around 


$10/wet ton 

+ $ll/ton freight 

(total = $21/ton) 


Sunkist, Tipton 


citrus peel 


year 
around 


$10/wet ton 

+ $10.50/ton freight 

(total = $20.50 to 

$22.50/ton) 


Coast Grain 


cattle manure 


spring and 
summer 


$20/ton incl .freight 
$3/ton to spread 


Harris Ranch 


cottonseed meal 
soybean meal 
saf flower meal 


year 
around 


$250/ton 
$280/ton 
$180/ton 


Water-Ways 


irrigation equipment: 







field equipment (lateral 
pipleline, risers, main- 
line, pumps) for 1200 ac 



$425,381 



11-8 



weight/ac on 1,280 acres at Kesterson would cost approximately $2.8 
million per year. With cottonseed meal at $250/t and an application 
rate of 2 t dry weight/ac ($500/ac) on 1,280 acres, the cost would be 
$1.3 million per year. The cost of applying cottonseed meal would be 
considerably less than citrus and is likely to be more effective in 
promoting volatilization as indicated by the San Luis Drain experiment. 
Furthermore, there is a limited supply of citrus pulp (orange or lemon 
peel) available for use. 

Filling of Ephemeral Pools 

The State Water Resource Control Board (SWRCB) considered the 
ephemeral pools at Kesterson Reservoir to be a significant threat to 
the biota. As a means to correct this problem, the SWRCB ordered the 
Bureau of Reclamation to fill these ephemeral pool areas to 6" above 
the rising water table. To our knowledge, the fill material is being 
added from a depth of 6" to as much as 8 feet in certain locations. 
Since much of the sediment is being covered with "clean" material, the 
application of volatilization as a remedial technique to remove the 
Se may not be as effective. This technique is only applicable to sur- 
face soils because it relies on i) aeration to selectively promote 
the soil fungal population and to allow the gaseous Se to diffuse into 
the atmosphere, ii) moisture to keep the topsoil moist, and iii) in- 
corporation of amendments to stimulate the microbial transformation. 



11-9 



If the seleniferous sediment is buried, these management techniques 
will be limited. With the current fill plan, the seleniferous sediments 
remain in pockets of "hot spots". Burial of the contaminated sediment 
will most likely extend the time needed for cleanup. 

One possible effective technique to extract the Se at lower depths 
would be to make use of cultivated vegetation for subsequent Se removal 
and treatment. Crop residues could be incorporated into the soil and 
provide additional C to stimulate microbial volatilization. In addi- 
tion, some higher plants are known to volatilize Se. Future research 
is needed to explore this integrated management scheme. 

At the present time, the field results indicate that soil volatili- 
zation of Se is an effective method to remove Se at Kesterson Reservoir, 
but not within a 2-year period as ordered by the State Water Resource 
Control Board. This work is in its infancy. Further studies are 
needed to determine other bioamendments that can accelerate microbial 
volatilization as a bioreclamation technique. 



12-1 



ACKNOWLEDGEMENTS 

This research was supported by the USDI Bureau of Reclamation 
Cooperative Agreement No. 7-FC-20-05240. We thank Susan Hoffman, 
Program Manager, for her support and Jim Esget for his help in the 
field. We wish to also recognize Andrew .Farrar, Dallas Linford, Gene 
Armand, and Louis Vasquez for their contributions to this operation. 
Special thanks to Noel Williams (CH2M Hill), Sally Benson and the LBL 
staff, and to Ed Lee and George Nishimura (San Joaquin Valley Drainage 
Program) for their input and suggestions. We wish to recognize the 
following personnel who helped us collect the data for this report: 
Karen Huysmans, laboratory manager; Brian Cahill and David Thomason, 
field managers; Roberta Wright, analytical chemist; David 01 sen, 
analytical chemist; Jodi Luther, computer operator; Dr. Lisa Thompson- 
Eagle, postdoctoral scientist; Ben Johanson, research assistant; Michael 
Carmo, field helper; Gordon Bradford, TCP specialist; Louise DeHayes, 
typist; and Joyce Thompson, typist. The soil analyses were performed 
by Karl Longley, Professor of Civil Engineering, California State 
University at Fresno, and the study on toxicity of dimethyl selenide 
was conducted by 0. G. Raabe, Professor of Environmental Health, 
University of California, Davis. 



R-1 
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Asher, C. J., C. S. Evans, and C. M. Johnson. 1967. Collection and 
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Birch, H. F. 1959. Further observations on humus decomposition and 
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Callister, S. M. , and M. R. Winfrey. 1986. Microbial methylation of 
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CH2M Hill. 1988. Air quality impacts of enhanced selenium volatiliza- 
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Reclamation. May, 1988. 



R-2 



Challenger, F. 1945. Biological methyl ati on. Chem. Rev. 36:315-361. 

Challenger, F., and P. T. Charlton. 1947. Studies on biological methyla- 
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moulds. J. Chem. Soc. 1947:424-429. 

Chau, Y. K. , P. T. S. Wong, B. A. Silverberg, P. L. Luxon, and 

G. A. Bengert. 1976. Methylation of selenium in the aquatic 
environment. Science 192:1130-1131. 

Cooke, T. D., and K. W. Bruland. 1987. Aquatic chemistry of sele- 
nium: Evidence of biomethylation. Environ. Sci. Technol . 21: 
1214-1219. 

Cox, D. P., and M. Alexander. 1974. Factors affecting trimethylarsine 
and dimethylselenide formation by Candida humicola . Microb. Ecol . 
1:136-144. 

Craig, P. J. 1986. Occurrence and pathways of organometall ic compounds 
in the envi ronment: General considerations, pp. 1-64. In: 
Organometallic Compounds in the Environment, Ed. P. J. Craig, 
Longman, Harlow, Essex, U.K. 

Davis, E. A., K. J. Maier, and A. W. Knight. 1988. The biological con- 
sequences of selenium in aquatic ecosystems. California Agricul- 
ture 1:18-29. 

Doran, J. W. and M. Alexander. 1977a. Microbial formation of volatile 
selenium compounds in soil. Soil Sci. Soc. Am. J. 41:70-73. 

Doran, J. W., and M. Alexander. 1977b. Microbial transformations of 
selenium. Appl . Environ. Microbiol. 33:31-37. 

Evans, C. S., and C. M. Johnson. 1966. The separation of some alkyl 

selenium compounds by gas chromatography. J. Chromatogr. 21:202-206. 



R-3 



Fleming, R.W. and M. Alexander. 1972. Dimethyl selenide and 

dimethyltelluride formation by a strain of PeniciHium . Applied 
Microbiol. 24:424-429. 

Francis, A. J., Duxbury, J. M. and Alexander, M. 1974. Evolution 
of dimethylselenide from soils. Applied Microbiol. 28:248-250. 

Frankenberger, W. T. Jr. and U. Karlson. 1988a. Microbial volatili- 
zation of selenium at Kesterson Reservoir, Interium Report March 
1988. Prepared for the U.S. Dept. of Interior, Bureau of 
Reclamation, Contract No. 7-FC-20-05240. 

Frankenberger, W. T., Jr., and U. Karlson. 1988b. Land treatment to 
detoxify soil of selenium. Patent disclosure filed June, 1988. 
Nilsson, Robbins, Dalgarn, Berliner, Carson and Wurst. Los 
Angeles, CA. Docket No. 4611-101. 

Ganje, T. J., and E. I. Whitehead. 1958. Evolution of volatile selenium 
from Pierre shale supplied with selenium-75 as selenite or selenate. 
Proc. S. Dak. Acad. Sci. 37:81-84. 

Ganther, H. E., 0. A. Levander, and C. A. Saumann. 1966. Dietary control 
of selenium volatilization in the rat. J. Nutrition 88:55-60. 

Harrison, H. 1987. WYNDvalley: An air-quality model for near-stagnant 
flows in constricted terrain. EPA-910/9-87-179. NTIS PB88-158969. 

Hsieh, H. S., and H. E. Ganther. 1975. Acid-volatile selenium forma- 
tion catalyzed by glutathione reductase. Biochemistry 14:1632-1636. 

Jager, G. , and E. H. Bruins. 1975. Effect of repeated drying at dif- 
ferent temperatures on soil organic matter decomposition and charac- 
teristics, and on soil microflora. Soil Biol. Biochem. 7:153-159. 



R-4 



Karlson, U. , and W. T. Frankenberger, Jr. 1986a. Determination of 

selenate by single-column ion chromatography. J. Chromatogr. 

368:153-161. 
Karlson, U. , and W. T. Frankenberger, Jr. 1986b. Single-column ion 

chromatography of selenite in soil extracts. Anal. Chem. 58: 

2704-2708. 
Karlson, U., and W. T. Frankenberger, Jr. 1987. Microbial volatiliza- 
tion of selenium by soils and pure fungal cultures. Agronomy 

Abstracts, 1987 Annual Meetings, American Society of Agronomy, 

Atlanta, GA, Nov. 29 - Dec. 4, p. 186. 
Karlson, U. and W. T. Frankenberger, Jr. 1988a. Determination of 

gaseous selenium-75 evolved from soil. Soil Sci. Soc. Am. J. 52: 

678-681. 
Karlson, U. and W. T. Frankenberger, Jr. 1988b. Effects of 

carbon and trace element addition on alkylselenide production 

by soil. Soil Sci. Soc. Am. J. (in press). 
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mineralogical methods. Am. Soc. Agronomy, Madison, WI. 
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its volatilization in higher plants, pp. 389-409. In: J. 0. 

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nitrogen, phosphorus. Sulfur and selenium cycles. Ann Arbor 

Science Publishers, Ann Arbor, MI. 



R-5 

Lewis, B. G. , Johnson, J. M. and Broyer, T. C. 1974. Volatile 

selenium in higher plants: the production of dimethylselenide in 

cabbage leaves by enzymatic cleavage of Se-methyl selenomethionine 

selenonium salt. Plant and Soil 40:107-118. 
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volatile selenium compounds by plants. Collection procedures and 

preliminary observations. Agric. Food Chem. 14:638-640. 
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metal cycles and predictions. Mathematical Geol . 11:99-141. 
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230-231. 
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R-6 



Skujins, J. J., L. Braal , and A. D. McLaren. 1962. Characteriza- 
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Toxicology 17:171-230. 



A-1 



APPENDIX A 
RAW DATA 



A- 



Table A-1. Alkyl selenide production monitored from Pond 4 at Kesterson 
Reservoir, October 1987 through January 1988. 



Subplot 












no. 


10/26/87 


10/27/87 


11/10/87 


12/16-17/87 


1/13/88 








-ug Se m" 


h-^ 












51 


19.8 


20.4 


12.2 


1.9 


20.2 


52 


37.4 


13.7 


7.5 


1.8 


29.7 


53 


34.3 


25.0 


14.0 


2.9 


81.1 


54 


20.4 


30.9 


25.5 


4.3 


18.5 


55 


37.8 


46.9 


15.6 


4.0 


S* 


56 


27.2 


7.3 


6.5 


2.5 


S 


57 


12.3 


2.3 


2.7 


2.0 


20.8 


58 


25.8 


18.3 


8.6 


4.7 


111.2 


59 


9.8 


12.9 


4.7 


2.4 


37.0 


60 


15.2 


17.2 


6.5 


3.5 


36.4 


61 


13.2 


18.6 


4.7 


12.8 


68.3 


62 


17.4 


1.6 


2.0 


1.0 


7.2 


63 


43.3 


65.3 


5.2 


2.2 


5.5 


64 


14.5 


10.0 


7.6 


1.3 


S 


65 


36.5 


5.6 


12.1 


1.1 


26.8 


66 


9.0 


1.0 


3.6 


0.5 


6.0 



♦Saturated with water 



A-3 



Table A-1 . Alkylselenide production monitored from Pond 4 at Kesterson 
Reservoir, February 1988 through March 1988. 



Subplot 












no. 


2/3/88 


2/23/88 


3/3/88 


3/17/88 


3/24-25/88 








■-yg Se m' 


h-L— — . 








(I — — — — — •- 




51 


3.6 


3.5 


2.0 


3.1 


10.0 


52 


6.8 


1.9 


3.3 


0.8 


12.8 


53 


14.0 


6.2 


11.5 


2.2 


21.4 


54 


S 


23.6 


32.8 


1.5 


10.4. 


55 


s 


S 


S 


S 


7.5- 


56 


s 


17.3 


30.9 


2.0 


12.4 


57 


s 


4.9 


16.6 


2.5 


8.2 


58 


29.9 


11.5 


23.8 


8.3 


21.5 


59 


26.4 


11.1 


39.1 


15.8 


32.0 


60 


3.8 


0.1 


1.2 


2.2 


7.2 


61 


45.9 


24.2 


31.1 


48.5 


77.6 


62 


S 


13.4 


23.5 


20.1 


16.0 


63 


S 


10.5 


30.6 


21.3 


41.4 


64. 


s 


7.6 


S 


S 


5.4 


65 


19.6 


4.5 


3.3 


5,1 


10.5 


66 


10.1 


2.7 


1.3 


0.2 


1.4 



*Satu rated with water 



A-^ 



Table A-1. Alkylselenide production monitored from Pond 4 at Kesterson 
Reservoir, April 1988 through May 1988. 



Subplot 
















no. 


4/4/88 


4/12/88 


4/20/88 


4/27/88 


5/10/88 


5/17/88 


5/24/88 










-yg Se m~ 


h-^ - 
















51 


8.3 


22.7 


2.4 


13.2 


5.1 


NO* 


6.1 


52 


13.2 


37.0 


4.9 


12.1 


13.7 


ND 


17.3 


53 


6.2 


22.6 


4.5 


16.8 


11.8 


ND 


7.9 


54 


0.4 


71.4 


40.9 


62.1 


13.0 


ND 


10.7 


55 


2.3 


28.4 


47.5 


131.3 


64.1 


3.4 


22.7 


56 


18.7 


73.7 


11.1 


28.0 


37.3 


0.5 


4.9 


57 


13.3 


62.2 


7.1 


24.1 


19.2 


0.5 


4.5 


58 


29.8 


70.2 


12.1 


56.5 


10.9 


0.5 


5.2 


59 


9.6 


40.9 


3.3 


122.6 


19.6 


0.6 


13.5 


60 


8.2 


16.7 


1.5 


2.6 


7.6 


0.5 


4.2 


61 


64.8 


212.1 


23.8 


124.6 


13.2 


0.8 


5.3 


62 


12.7 


102.8 


11.1 


35.5 


35.7 


0.9 


10.9 


63 


11.4 


357.3 


74.4 


94.1 


47.9 


4.8 


24.8 


64 


0.7 


119.5 


18.4 


30.1 


10.0 


0.8 


1.5 


65 


9.7 


23.7 


10.0 


34.0 


8.4 


6.3 


21.4 


66 


0.5 


4.7 


2.9 


7.2 


4.6 


3.2 


5.7 



*ND, not detectable 



A-5 



Table A-1. Alkylselem'de production monitored from Pond 4 at Kesterson 
Reservoir, June 1988 through July 1988. 



Subplot 


















no. 


6/3/88 


6/17/88 


6/24/88 


7/6/88 


7/13/88 


7/18/88 


7/19/88 


7/25/88 










-^^^^^•■n ^Q 


m-2 h-^- 
















yg ie 




51 


9.7 


5.8 


18.0 


21.1 


38.8 


8.6 


11.6 


18.1 


52 


18.6 


37.9 


185.2 


70.6 


143.6 


8.8 


47.3 


177.1 


53 


13.2 


14.4 


55.0 


31.2 


116.1 


34.1 


69.9 


24.8 


54 


39.7 


25.5 


52.5 


21.0 


276.0 


40.9 


113.6 


19.3 


55 


15.8 


175.4 


328.2 


199.9 


391.0 


58.6 


220.7 


268.2 


56 


19.3 


10.7 


49.7 


33.4 


167.3 


24.6 


61.3 


41.7 


57 


37.1 


36.4 


55.3 


74.2 


133.1 


9.8 


63.4 


15.0 


58 


7.5 


21.8 


69.3 


10.8 


180.5 


39.8 


37.9 


13.2 


59 


5.8 


183.9 


89.4 


32.3 


23.5 


5.7 


38.0 


148.4 


60 


6.9 


18.5 


33.0 


33.4 


96.1 


13.5 


26.9 


16.6 


61 


31.3 


18.8 


61.2 


47.0 


297.3 


94.3 


105.8 


65.3 


62 


20.9 


80.7 


71.1 


140.6 


97.9 


31.1 


13.8 


16.1 


63 


79.5 


216.5 


144.3 


368.5 


346.2 


76.0 


149.5 


40.6 


64 


3.7 


24.8 


39.2 


33.5 


419.0 


20.9 


313.1 


39.9 


65 


31.6 


41.7 


30.9 


72.2 


98.1 


27.8 


40.2 


20.2 


66 


2.6 


5.2 


6.3 


7.9 


26.4 


21.3 


23.3 


14.9 



A- 6 



Table A-1. Alkylselenide production monitored from Pond 4 
at Kesterson Reservoir during August 1988. 



Subpl 


ot 










no. 


8/1/88 


8/8/88 


8/12/88 


8/23/88 


8/30/88 






.«. — *» — •* — II n 


9p m h 


•1 




51 


35.2 


17.3 


OC 111 '• 

3.2 


11.5 


13.7 


52 


103.4 


40.4 


80.1 


61.4 


49.3 


53 


46.5 


34.6 


15.4 


35.9 


73.3 


54 


16.7 


433.6 


270.0 


93.2 


211.4 


55 


200.5 


155.1 


145.4 


137.2 


93.8 


56 


92.1 


35.6 


10.3 


33.5 


31.2 


57 


29.2 


31.3 


13.3 


28.1 


26.2 


58 


0.1 


41.6 


137.9 


56.9 


104.0 


59 


20.2 


52.9 


34.6 


47.3 


34.9 


60 


7.2 


6.2 


0.6 


11.5 


18.8 


61 


20.5 


701.5 


144.3 


79.9 


138.4 


62 


21.9 


41.1 


12.5 


24.4 


23.2 


63 


122.0 


808.5 


376.0 


576.6 


749.2 


64 


36.5 


153.0 


212.2 


214.8 


160.0 


65 


181.4 


311.7 


272.1 


259.2 


88.2 


66 


39.1 


18.6 


24.5 


30.9 


38.0 



A-7 



Table A-1. Alkylselenide production monitored from Pond 4 
at Kesterson Reservoir during September 1988. 



Subplot 












no. 


9/6/88 


9/15/88 


9/19/88 


9/21/88 


9/29/88 






>MM_.«M__iin 


Se m"^ h"^ 










uy 




51 


5.4 


1.3 


4.4 


1.8 


3.1 


52 


23.1 


5.2 


13.7 


28.7 


32.4 


53 


23.9 


29.7 


20.9- 


37.3 


23.2 


54 


83.4 


28.1 


36.8 


52.9 


10.1 


55 


110.0 


119.8 


33.7 


35.1 


25.0 


56 


8.1 


11.7 


9.8 


10.0 


24.5 


57 


27.9 


5.1 


9.2 


16.0 


8.8 


58 


30.5 


18.9 


23.6 


30.9 


16.7 


59 


8.3 


4.5 


9.4 


29.7 


37.8 


60 


5.4 


NO 


8.4 


5.1 


3.4 


61 


77.9 


26.3 


8.9 


56.4 


11.0 


62 


14.3 


5.0 


6.0 


20.2 


15.1 


63 


457.8 


448.6 


213.0 


619.2 


211.2 


64 


199.0 


69.0 


63.9 


135.2 


464.0 


65 


4.2 


83.6 


22.0 


58.9 


38.3 


66 


32.7 


38.3 


22.3 


30.4 


11.7 



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*1- 



I 

CM 



00 



I 

00 



CO 

o 



LO 
CO 



ro 

LO 



<n 
ro 



LD 



CO 



':a- 


«— t 


CM 


LD 


o 


o 


LO 


CO 



LO «— < 



CO 

I 

CO 
00 



CO 

o 



00 



LO 

00 

LO 



00 

LO 



I 



CM 
1^ 



CO 

LO 

I 



CM 

ro 



en 



LO 
LO 


LO 

o 


00 
CM 


CO 

o 


ro 


<n 
.—1 


ro 

.—I 


i — t 
1— ( 


o 

CM 


00 


00 


o 

00 



in 

CM 



LO 
CM 



en 



CO 

CO 



CM 



LO 


CO 


CM 


in 


r~ 


VO 


^ 


CM 


CM 


CO 


CO 


I— 1 



p~. 
ro 



CM 



I — 



00 



in 



CO 

o 



o 
o 


o 
o 


o 
o 


o 
o 


o 
o 


o 
o 


o 
o 


O 
O 


O 
O 


o 
o 


o 

o 


O 
O 


o 
o 


o 
o 


00 


as 


o 

1—1 


r-l 
T-H 


CM 

1— t 


ro 

1— t 




LO 


LO 

1-H 




o 

CM 


"a- 

CM 


«=r 


CO 



Table A-3. 


Spatial 


variability of the 


inventory se" 


en i urn 




content 


at Pond 4, Kesterson Reservoir. 




Subplot 


Sample 


Duplicate 


Average 


RPD, % 






,__^__^^^^^ mn L'n 


-1 








------------- -iny K y 




51Ai 


37.95 


37.89 


37.92 


0.16 


51Bi 


37.00 


36.11 


36.56 


2.43 


51Ci 


33.25 


37.77 


35.51 


12.73 


51Di 


9.92 


10.09 


10.01 


1.70 


51Ei 


21.89 


21.79 


21.84 


0.46 


52Ai 


35.65 


34.93 


35.29 


2.04 


52Bi 


123.49 


124.84 


124.17 


1.09 


59Ci 


60.20 


58.58 


59.39 


2.73 


52Di 


75.02 


74.02 


74.52 


1.34 


52Ei 


60.56 


64.32 


62.44 


6.02 


53Ai 


36.07 


37.89 


36.98 


4.92 


53Bi 


. 42.79 


44.14 


43.47 


3.11 


53Ci 


36.29 


36.48 


36.39 


0.52 


53Di 


35.75 


35.80 


35.78 


0.15 


53Ei 


37.92 


38.61 


38.27 


1.80 


54Ai 


29.23 


28.75 


28.99 


1.66 


54Bi 


27.26 


26.78 


27.02 


1.78 


54Ci 


25.87 


26.02 


25.95 


0.58 


54Di 


30.97 


29.97 


30.47 


3.28 


54Ei 


28.37 


30.32 


29.35 


6.65 


55Ai 


88.98 


86.59 


87.79 


2.72 


55Bi 


61.48 


&1.50 


61.49 


0.03 


55Ci 


132.37 


133.59 


132.98 


0.92 


55Di 


104.28 


100.40 


102.34 • 


3.79 


55Ei 


28.70 


29.38 


29.04 


2.34 


56Ai 


117.01 


106.33 


111.67 


9.56 


56Bi 


37.44 


39.19 


38.32 


4.57 


56Ci 


81.37 


81.95 


81.66 


0.71 


56Di 


210.89 


206.92 


208.91 


1.90 


56Ei 


76.96 


74.32 


75.64 


3.49 


57Ai 


136.37 


133.73 


135.05 


1.95 


57Bi 


41.64 


40.75 


41.20 


2.16 


57Ci 


75.90 


72.99 


74.45 


3.91 


57Di 


34.10 


34.23 


34.17 


0.38 


57Ei 


47.42 


48.99 


48.21 


3.26 


58Ai 


18.51 


18.87 


18.69 


1.93 


58Bi 


35.26 


33.80 


34.53 


4.23 


58Ci 


42.81 


46.28 


44.55 


7.79 


58Di 


66.35 


71.95 


69.15 


8.10 


58Ei 


25.17 


24.04 


24.61 


4.59 



A-9 



Tabl 


e A-3. (continued) 








Subplot Sample 


Duplicate 


Average 


RPD, % 






- — — — — — — — — mn 


kg-^ 








— ^ — ■■ — — ^^^Ujy 




59A] 


[ 22.58 


22.44 


22.51 


0.62 


59B] 


31.52 


32.50 


32.01 


3.06 


59C 


[ 22.03 


21.90 


21.97 


0.59 


59D] 


[ 37.96 


36.58 


37.27 


3.70 


59E] 


L 68.54 


69.39 


68.97 


1.23 


60A] 


L 24.29 


24.08 


24.19 


0.87 


60B] 


[ 47.64 


43.60 


45.62 


8.86 


60C- 


L 18.23 


17.54 


17.89 


3.86 


60D- 


[ 22.13 


20.48 


21.31 


7.74 


60E; 


L 38.72 


37.93 


38.33 


2.06 


61A] 


[ 49.72 


48.02 


48.87 


3.48 


61B] 


[ 40.55 


39.68 


40.12 


2.17 


61C] 


[ 19.14 


18.97 


19.06 


0.89 


61D- 


[ 39.87 


37.81 


38.84 


5.30 


61E] 


L 61.20 


63.28 


62.24 


3.34 


62A] 


66.52 


68.88 


67.70 


3.49 


62B] 


44.80 


42.86 


43.83 


4.43 


62C] 


; 59.49 


58.94 


59.22 


0.93 


62D- 


L 37.84 


38.16 


38.00 


0.84 


62E] 


L 50.51 


51.10 


50.81 


1.16 


63A] 


61.55 


62.25 


61.90 


1.13 


638] 


61.91 


62.86 


62.39 


1.52 


63C] 


L 33.97 


34.41 


34.19 


1.29 


63D] 


L 15.58 


16.12 


15.85 


3.41 


63E] 


L 32.50 


35.22 


33.86 


8.03 


64A] 


L 50.64 


50.10 


50.37 


1.07 


64B- 


L 125.95 


127.49 


126.72 


1.22 


64C' 


[ 52.47 


54.44 


53.46 


3.69 


64D 


[ 48.74 


49.82 


49.28 


2.19 


64E; 


L 18.69 


19.22 


18.96 


2.80 


65A] 


[ 51.41 


51.68 


51.55 


0.52 


65B] 


[ 74.22 


72.48 


73.35 


2.37 


65C] 


[ 62.63 


64.67 


63.65 


3.21 


65D] 


L 39.47 


40.10 


39.79 


1.58 


65E] 


L 46.51 


43.45 


44.98 


6.80 


66A] 


L 32.57 


33.07 


32.82 


1.52 


66B] 


[ 28.38 


29.08 


28.73 


2.44 


66Ci 


L 33.91 


33.70 


33.81 


0.62 


66D- 


L 23.52 


25.61 


24.57 


8.51 


66E1 


[ 24.43 


22.54 


23.49 


8.05 



A-n 



Table A-4. 



Selenium content of Kesterson sediment at Pond 4, 
September, 1987 through January, 1988. 



Subplot 

no. 



Sept. 87 



Oct. 87 



Nov. 87 



Dec. 87 



Jan. 88 



-1 



51 


27.1 


;ioo)* 


20.3 


52 


50.5 


,100) 


50.6 


53 


57.7 


;ioo) 


48.4 


54 


40.0 


.100) 


36.0 


55 


68.2 


;ioo) 


65.4 


56 


81.6 


,100) 


71.4 


57 


54.3 


;ioo) 


58.7 


58 


35.7 


,100) 


35.0 


59 


31.7 


,100) 


32.7 


60 


35.5 


;ioo) 


33.5 


61 


52.2 


;ioo) 


46.4 


62 


71.7 


;ioo) 


52.4 


63 


78.9 


;ioo) 


58.0 


64 


65.4 


Uoo) 


40.8 


65 


83.2 


;ioo) 


48.8 


66 


34.2 


uoo) 


29.5 



( 74. 


9) 


(100. 


2) 


( 83. 


9) 


( 90. 


0) 


( 95. 


9) 


( 87. 


6) 


(108. 


1) 


( 98. 


0) 


(103. 


1) 


( 94. 


3) 


( 88 


.9) 


( 73. 


.0) 


( 73. 


6) 


( 62 


3) 


( 58 


7) 


( 86 


.2) 



— liiy f 

20.2 


^y 

74.5) 


18.4 ( 


67.9) 


19.0 ( 


70.1) 


55.8 


110.5) 


48.4 


95.8) 


58.6 ( 


116.0) 


50.1 


86.8) 


40.6 


70.3) 


40.7 ( 


70.6) 


39.6 


99.0) 


28.9 ( 


72.2) 


32.7 ( 


81.8) 


80.8 


118.4) 


67.1 


. 98.3) 


73.9 ( 


108.3) 


85.9 


105.2) 


66.0 


80.9) 


79.6 


97.6) 


71.6 


131.9) 


46.7 


86.0) 


52.9 ( 


97.4) 


36.0 


100.9) 


31.1 


87.1) 


33.3 


93.2) 


33.7 


106.3) 


31.7 


100.0) 


29.3 


, 92.4) 


34.3 


96.7) 


34.6 


97.4) 


35.0 


. 98.6) 


54.3 


104.0) 


41.0 


, 78.6) 


47.1 


90.2) 


66.0 ( 


92.0) 


50.3 


[70.1) 


60.0 


, 83.7) 


60.7 


77.0) 


59.2 


, 75. '0) 


66.7 


, 84.6) 


46.9 


71.8) 


45.9 


, 70.1) 


38.0 


, 58.1) 


56.4 


67.8) 


46.4 


; 55.8) 


48.0 


; 57.7) 


36.2 


[105. 9) 


32.7 


. 95.7) 


43.5 


.127.1) 



^Figures in parentheses represent percentage of selenium content remaining after 
the specified time period. 



Table A-4. Selenium content of Kesterson sediment at Pond 4, 
March, 1988 through July, 1988. 



Subplot 








« 












i 


no. 


Mar 


'.87 


Apr 


87 


May 


87 


Jun 


87 


Jul. 


88 












^ mri 1 


,0-1 




















— — iiiy 1 


-9 










51 


20.6 


; 76.0) 


19.1 


. 70.5) 


20.6 


76.0) 


22.1 


81.5) 


22.9 


84 


52 


52.6 


104.1) 


44.7 


88.6) 


37.2 


73.7) 


38.8 


76.9) 


37.0 


73 


53 


40.1 


. 69.4) 


37.5 


65.0) 


34.2 


59.2) 


44.4 


77.0) 


47.5 


82 


54 


31.8 


. 79.6) 


28.4 


71.0) 


26.1 


65.2) 


25.4 


63.6) 


30.3 


75 


55 


65.9 


. 96.7) 


65.1 


95.4) 


54.2 


. 79.4) 


60.7 


89.0) 


63.7 


93 


56 


65.7 


80.6) 


62.1 


76.1) 


54.7 


67.0) 


58.8 


72.0) 


57.5 


70 


57 


53.9 


99.2) 


53.1 


97.8) 


48.8 


89.9) 


57.3 


105.6) 


47.0 


86 


58 


30.8 


86.2) 


30.8 


86.2) 


29.2 


81.8) 


38.9 


109.0) 


28.4 


79 


59 


27.0 


85.1) 


31.0 


97.8) 


29.3 


92.4) 


33.7 


106.3) 


29.7 


93 


60 


31.6 


89.0) 


28.8 


81.1) 


30.4 


. 85.7) 


36.6 


103.0) 


31.8 


89 


61 


42.4 


81.2) 


42.6 


81.7) 


40.9 


78.3) 


41.6 


79.7) 


41.5 


74 


62 


55.6 


. 77.6) 


46.9 


65.4) 


47.8 


66.7) 


47.8 


. 66.7) 


44.7 


62 


63 


51.8 


; 65.7) 


51.8 


65.7) 


46.5 


. 59.0) 


53.6 


68.0) 


47.0 


59 


64 


41.7 


, 63.8) 


40.4 


61.8) 


45.1 


69.0) 


44.1 


57.4) 


40.8 


62 


65 


50.1 


; 60.2) 


43.7 


52.6) 


42.5 


51.0) 


42.8 


. 51.4) 


34.8 


41 


66 


34.2 


,100. 0) 


32.1 


93.9) 


31.1 


91.0) 


25.7 


. 75.1) 


19.6 


57 



Table A-5. Profile distribution of selenium at Pond 4, 
Kesterson Reservoir. 



A-13 





Depth 




Selenium content (mg kg"^ soil) 






Subplot 


Jul. 


1987 


Nov. 1987 Jan. 88 


Jul. 


88 




(■ 


n. ) 


(29) 


(24-25) (19) 


(24) 


51 


0- 


■6 


4.7 


(2.79)* 


17.1 (3.05) 


16.7 


(5.80) 


51 


6- 


■12 


ND' 


Ir* 


ND 


2.1 




51 


12- 


-18 


ND 




ND 


3.4 




51 


18- 


-24 


ND 




ND 


ND 




52 


0- 


-6 


17.9 


(1.90) 


17.0 (6.65) 


5.6 




52 


6- 


-12 


3.1 


(10.53) 


ND 


ND 




52 


12- 


-18 


ND 




4.3 (1.87) 


1.0 




52 


18- 


-24 


ND 




ND 


ND 




53 


0- 


-6 


16.5 


(6.56) 


37.5 (2.62) 


12.1 




53 


6- 


-12 


5.9 


(0.00) 


ND 


1.2 




53 


12- 


■18 


3.1 


(6.37) 


ND 


9.5 




53 


18- 


■24 


ND 




ND 


1.4 




54 


0- 


■6 


8.8 


(5.23) 


7.0 (4.16) 


15.8 


(7.69) 


54 


6- 


■12 


ND 




ND 


1.1 




54 


12- 


■18 


ND 




ND 


4.1 




54 


18- 


■24 


ND 




ND- 


1.3 




55 


0- 


■6 


18.1 




33.4 (2.70) 


26.1 




55 


6- 


■12 


1.8 




1.7 (4.68) 


2.4 




55 


12- 


■18 


ND 




ND 


3.3 




55 


18- 


■24 


1.3 


(3.95) 


ND 


ND 




56 


0- 


■6 


23.5 


(0.64) 


34.3 (4.20) 


19.8 




56 


6- 


■12 


1.8 


;i4.53) 


ND 


2.3 




56 


12- 


•18 


ND 




3.7 (0.82) 


13.6 




56 


18- 


■24 


ND 




ND 


1.2 




57 


0- 


■6 


15.0 


(1.40) 


12.6 (6.29) 


18.5 




57 


6- 


■12 


ND 




ND 


4.6 




57 


12- 


■18 


ND 




2.9 (3.84) 


3.8 




57 


18- 


■24 


1.3 


(2.41) 


ND 


1.6 




58 


0- 


•6 


57.3 


(5.90) 


17.0 (3.48) 


11.8 


(16.19) 


58 


6- 


■12 


1.8 


,23.10) 


ND 


12.9 




58 


12- 


■18 


1.0 


(2.93) 


1.1 (2.79) 


5.0 




58 


18- 


-24 


ND 




1.1 (4.65) 


3.9 





A-14 



Table A-5. 


(continued) 




















Depth 


Sel 


enium ( 


:ontent 


(mg 


kg- 


■^ soil) 






Subplot 


Jul. 1987 


Nov.: 


1987 


J, 


an. 


,88 


Jul. 88 






(- 


i n. ) 


(29) 


(25) 




(19) 


(24) 




59 


0- 


-6 


20.5(11.02) 


15.1 


(8.52) 


34 


.1 


(2.12) 


15.9 




59 


6- 


-12 


ND 


1.0 


(4.88) 


5 


.2 


(14.08) 


3.7 




59 


12- 


-18 


ND 


1.6 1 


(13.92) 




N[ 


) 


3.2 




59 


18- 


-24 


ND 


ND 






N[ 


) 


3.9 




60 


0- 


-6 


10.2 (3.13) 


16.6 


(1.69) 








10.1 




60 


6- 


-12 


ND 


2.5 


(0.79) 








1.4 




60 


12- 


-18 


ND 


ND 










2.3 




60 


18- 


-24 


ND 


ND 










ND 




61 


0- 


-6 


18.1 (0.39) 


15.9 


(1.20) 








14.8 (12.37) 


61 


6- 


-12 


ND 


ND 










2.1 




61 


12- 


■18 


1.5(11.76) 


1.1 


(3.77) 








3.4 




61 


18- 


-24 


ND 


ND 










ND 




62 


0- 


-6 


16.8 (0.18) 


31.3 


(3.26) 








12.6 




62 


6- 


•12 


ND 


1.56 


(3.85) 








3.1 




62 


12- 


■18 


1.4 (9.1) 


ND 










ND 




62 


18- 


■24 


ND 


ND 










ND 




63 


0- 


•6 


10.2 (6.89) 


51.8 


(1.80) 


29, 


.6 


(37.68) 


15.0 


31.7 


63 


6- 


•12 


ND 


2.43 


(2.06) 


12, 


.5 


(14.78) 


2.58 


2.1 


63 


12- 


•18 


ND 


1.16 


(4.33) 


1, 


.23(10.61) 


4.33 


2.3 


63 


18- 


•24 


ND 


ND 




3. 


.52 


! (3.97) 


1.08 


ND 


64 


0- 


■6 


4.6(20.59 ) 


9.52 


(5.04) 








6.6 




64 


6- 


•12 


2.7 (3.29) 


ND 










1.5 




64 


12- 


•18 


ND 


2.66 


(0.75) 








ND 




64 


18- 


•24 


ND 


ND 










2.0 




65 


0- 


•6 








39, 


.5 


(9.68) 


9.1 




65 


6- 


•12 








15. 


.5 


(1.48) 


ND 




65 


12- 


■18 








2, 


.2 


(2.32) 


3.9 




65 


18- 


•24 










NC 


1 


2.8 




66 


0- 


•6 








32, 


.2 


(7.02) 


8.0 (2.47) 


66 


6- 


•12 








4, 


.2 


(2.38) 


1.2 




66 


12- 


•18 








3, 


,4 


(4.07) 


4.8 




66 


18- 


■24 








1, 


J 


(0.58) 


ND 





♦Figures in parentheses indicate RPD, % 
**not detected 



A-15 



Table A-6. Alkylselenide production monitored from Pond 11 at Kesterson Reservoir, 
October 1987 through February 1988. 



Subplot 
















no. 


10/15-17/87 


11/9/87 


12/16-17/87 


1/14-19/88 


1/21-22/88 


2/3/88 


2/4/88 








»____««. ..i.n 


Se m"^ h"^- 














ug 




1 


16.80 


8.30 


1.98 


9.01 


2.28 


2.93 


2.81 


2 


1.08 


0.63 


0.91 


5.87 


1.52 


1.78 


3.13 


3 


15.20 


8.46 


3.25 


20.04 


3.04 


3.07 


5.64 


4 


10.20 


3.60 


4.67 


10.01 


26.60 


5.64 


1.41 


5 


3.70 


0.53 


1.40 


5.51 


6.46 


3.70 


1.37 


6 


0.23 


0.59 


1.58 


4.50 


2.28 


1.41 


1.96 


7 


ND 


1.50 


1.67 


12.77 


1.52 


1.55 


2.86 


8 


0.22 


1.41 


2.78 


7.25 


1.14 


3.62 


6.31 


9 


ND 


0.28 


2.04 


5.68 


4.18 


1.72 


1.14 


10 


2.81 


6.92 


2.14 


11.05 


1.14 


1.65 


1.61 


11 


ND 


1.29 


1.65 


12.44 


1.52 


2.42 


2.35 


12 


ND . 


5.01 


4.76 


25.63 


11.40 


6.71 


2.82 


13 


4.69 


4.00 


2.08 


9.01 


1.14 


1.65 


2.96 


14 


ND 


ND 


1.88 


3.29 


2.66 


1.11 


1.71 


15 


1.61 


4.21 


2.51 


8.00 


2.66 


1.98 


1.76 


16 


ND 


1.19 


3.89 


8.48 


1.90 


2.99 


3.56 


17 


0.86 


1.13 


2.81 


9.36 


4.18 


2.05 


2.40 


18 


4.71 


4.71 


3.91 


4.36 


1.90 


3.04 


2.48 


19 


4.36 


4.27 


3.72 


5.74 


1.90 


1.84 


1.86 


20 


1.04 


7.44 


3.46 


7.59 


3.8 


2.51 


3.06 


21 


7.18 


4.16 


1.94 


12.27 


2.66 


3.20 


3.78 


22 


3.26 


2.18 


1.36 


2.27 


1.52 


1.45 


1.34 


23 


0.41 


1.91 


2.05 


6.48 


2.28 


1.32 


1.85 


24 


2.18 


2.76 


1.79 


1.67 


1.52 


1.88 


1.67 


25 


0.59 


2.80 


1.34 


6.20 


8.74 


3.17 


1.39 


26 


ND 


3.00 


1.87 


3.68 


4.94 


3.01 


1.69 


27 


ND 


0.93 


0.72 


3.79 


1.90 


1.88 


1.69 


28 


4.01 


3.61 


2.25 


5.65 


2.28 


2.87 


2.31 


29 


ND 


0.49 


1.41 


4.48 


5.70 


2.43 


2.59 


30 


3.54 


2.19 


2.07 


11.87 


12.54 


3.68 


2.31 



*ND, not detected 



Table A- 


-6. Alkylsel 


enide production monitored from 


Pond 11 at 


Kesterson 






Reservoir, Februa 


ry 1988 th 


rough April ] 


L988. 






Subplot 
















no. 


2/22-23/88 


3/3/88 


3/16/88 


3/24-25/88 


4/12-14/88 


4/22/88 


4/28/88 










_ ,, n Co m h 


■1 






1 


4.16 


1.80 


2.64 


\i)j Oc 111 II 

1.53 


1.94 


3.05 


1.82 


2 


2.52 


0.67 


0.68 


ND 


3.11 


6.21 


1.74 


3 


3.69 


2.30 


7.65 


6.59 


5.46 


5.10 


5.24 


4 


2.55 


4.91 


5.38 


ND 


1.27 


3.39 


6.38 


5 


3.06 


0.65 


1.16 


0.50 


0.77 


2.36 


1.97 


6 


2.04 


0.01 


0.45 


ND 


0.54 


0.77 


0.42 


7 


2.76 


0.66 


0.85 


1.52 


1.39 


1.81 


0.91 


8 


6.56 


3.30 


3.38 


2.34 


2.42 


3.80 


4.34 


9 


2.80 


0.49 


1.09 


0.63 


1.63 


1.96 


1.11 


10 


2.78 


1.52 


3.08 


5.90 


1.79 


2.64 


3.41 


11 


2.93 


1.78 


1.81 


1.74 


1.74 


3.26 


5.90 


12 


4.22 


1.82 


2.47 


1.64 


1.23 


1.81 


2.81 


13 


2.37 


0.27 


1.76 


0.58 


4.00 


3.57 


5.20 


14 


' 0.85 


0.34 


0.28 


ND 


1.3 


3.56 


3.10 


15 


1.87 


3.61 


4.00 


0.94 


1.78 


2.53 


10.00 


16 


3.47 


2.58 


1.53 


ND 


0.6 


3.42 


4.27 


17 


1.62 


1.66 


0.10 


ND 


0.14 


5.20 


3.97 


18 


3.15 


2.81 


3.84 


2.85 


2.31 


7.23 


7.26 


19 


1.87 


1.77 


2.77 


0.82 


0.9 


3.01 


2.58 


20 


5.46 


3.75 


4.20 


1.69 


1.52 


4.06 


5.94 


21 


5.09 


4.34 


3.31 


3.83 


1.37 


11.56 


7.21 


22 


1.12 


2.27 


0.20 


0.18 


0.33 


1.34 


1.54 


23 


1.78 


2.54 


1.18 


0.35 


0.82 


3.99 


2.96 


24 


1.79 


1.49 


2.47 


2.33 


1.45 


2.75 


0.52 


25 


1.26 


4.72 


0.46 


1.32 


4.06 


2.62 


2.46 


26 


1.72 


2.74 


2.59 


1.73 


3.04 


3.41 


7.96 


27 


1.35 


1.31 


0.44 


0.77 


0.76 


3.30 


4.47 


28 


2.96 


3.05 


3.21 


1.53 


1.81 


9.45 


5.92 


29 


1.05 


1.27 


1.85 


ND 


1.23 


7.92 


7.34 


30 


2.10 


2.31 


1.02 


0.85 


1.08 


6.75 


3.38 



*ND, not detected 



A-17 



Table A-6. Alkylselenide production monitored from Pond 11 at Kesterson Reservoir, 
May 1988 through July 1988. 



Subplot 
















no. 


5/9/88 


5/18/88 


5/23/88 


6/8/88 


6/23/88 


7/7/88 


7/15/88 








--. — — ~ — — — iifT *^P 


n"2 h-^-- 








1 


ND 


1.50 


uy jc 
ND 


III 1 1 

2.40 


1.16 


3.50 


9.20 


2 


ND 


2.09 


ND 


4.42 


5.43 


18.12 


22.01 


3 


6.46 


5.41 


ND 


2.50 


ND 


2.15 


12.23 


4 


1.23 


1.76 


ND 


4.61 


1.85 


4.62 


21.42 


5 


1.07 


2.18 


ND 


3.09 


2.29 


2.51 


14.37 


6 


ND 


3.06 


ND 


2.61 


ND 


1.14 


6.76 


7 


0.20 


0.88 


3.05 


2.31 


1.00 


0.81 


10.16 


8 


1.80 


0.84 


6.03 


3.34 


3.29 


6.43 


21.64 


9 


ND 


1.47 


5.17 


2.65 


2.68 


16.24 


11.44 


10 


5.38 


2.57 


5.49 


1.25 


1.14 


2.65 


10.03 


11 


2.36 


2.73 


8.91 


3.12 


5.25 


2.96 


9.91 


12 


ND 


ND 


7.14 


2.05 


2.08 


1.58 


5.80 


13 


5.38 


0.73 


6.07 


3.04 


1.07 


9.28 


7.92 


14 


2.35 


ND 


2.95 


1.29 


0.15 


4.61 


5.80 


15 


7.10 


ND 


1.05 


1.25 


ND 


3.81 


9.69 


16 


3.20 


ND 


0.60 


6.19 


0.90 


2.24 


19.15 


17 


2.42 


ND 


0.51 


3.81 


0.54 


2.04 


4.62 


18 


12.61 


ND 


0.74 


2.59 


0.61 


4.97 


7.89 


19 


2.53 


ND 


0.25 


0.34 


0.87 


3.22 


7.09 


20 


3.57 


ND 


2.75 


2.95 


3.39 


17.56 


5.31 


21 


10.48 


ND 


1.58 


2.33 


1.46 


4.60 


6.08 


22 


2.31 


0.17 


0.37 


0.37 


0.50 


9.26 


10.51 


23 


5.40 


0.36 


ND 


6.71 


1.63 


1.02 


7.03 


24 


0.06 


1.29 


ND 


0.86 


0.51 


ND 


5.78 


25 


2.64 


1.28 


0.15 


2.26 


1.38 


5.48 


7.49 


26 


4.39 


2.01 


ND 


0.20 


0.69 


1.06 


5.11 


27 


4.48 


0.80 


ND 


1.13 


0.41 


ND 


1.58 


28 


4.04 


0.93 


ND 


ND 


0.23 


1.65 


1.82 


29 


3.75 


1.10 


ND 


5.80 


0.32 


3.71 


4.67 


30 


0.90 


0.76 


0.22 


0.78 


0.09 


0.52 


0.36 



*ND, not detected 



A-18 



Table A-6. Alkylselenide production monitored from Pond 11 at Kesterson Reservoir during 
August and September 1988. 



Subplot 


















no. 


8/2/88 


8/11/88 


8/29/88 


9/9/88 


9/14/88 


9/20/88 


9/23/88 


9/28/S 


1 


1.72 


1.09 


1.33 


0.01 


0.71 


0.82 


5.92 


2.68 


2 


62.35 


18.73 


16.08 


7.46 


11.23 


2.40 


26.22 


65.30 


3 


3.00 


0.75 


1.44 


ND 


0.76 


0.50 


1.66 


2.23 


4 


ND 


17.86 


9.71 


2.07 


1.29 


0.45 


6.50 


2.29 


5 


88.15 


22.82 


4.55 


6.34 


11.23 


1.40 


17.63 


57.50 


6 


1.65 


0.91 


2.51 


ND 


1.02 


ND 


3.29 


2.11 


7 


1.78 


0.96 


2.24 


2.20 


2.29 


0.54 


4.08 


3.20 


8 


1.45 


11.63 


10.58 


4.28 


4.96 


0.97 


7.84 


2.36 


9 


56.25 


17.88 


8.67 


7.61 


0.39 


1.53 


15.65 


120.40 


10 


2.23 


1.03 


4.40 


1.44 


0.08 


1.47 


4.10 


3.24 


11 


1.54 


7.11 


8.77 


2.46 


2.04 


1.79 


7.32 


3.08 


12 


3.15 


1.43 


3.62 


1.99 


ND 


1.37 


7.88 


0.26 


13 


1.27 


8.56 


17.19 


2.50 


0.47 


1.47 


5.31 


0.99 


14 


2.32 


0.59 


1.75 


2.66 


ND 


1.58 


• 2.59 


0.24 


15 


0.97 


2.04 


3.01 


1.50 


2.20 


0.62 


3.95 


0.75 


16 


8.03 


4.15 


9.64 


1.16 


2.15 


1.39 


3.98 


1.30 


17 


2.69 


0.75 


5.24 


0.50 


1.15 


0.61 


4.01 


1.53 


18 


3.71 


4.46 


3.81 


0.13 


3.62 


0.42 


8.60 


3.34 


19 . 


0.61 


0.50 


0.80 


1.10 


0.98 


0.17 


0.16 


0.62 


20 


1.57 


1.29 


2.99 


ND 


1.02 


0.24 


1.05 


2.57 


21 


0.87 


0.74 


0.90 


ND 


1.36 


ND 


0.82 


1.44 


22 


1.21 


7.70 


3.74 


3.69 


1.24 


0.51 


4.64 


1.79 


23 


3.21 


3.83 


2.76 


7.49 


1.29 


0.25 


6.93 


lo97 


24 


1.73 


0.84 


4.05 


1.45 


ND 


0.09 


5.63 


1.21 


25 


ND 


13.98 


11.25 


6.59 


4.25 


0.76 


11.69 


4.12 


26 


0.94 


2.36 


3.89 


1.96 


0.11 


0.18 


5.42 


0.94 


27 


2.61 


1.96 


2.90 


4.08 


ND 


1.18 


3.36 


0.86 


28 


3.76 


3.90 


6.32 


3.86 


0.47 


0.97 


5.14 


1.29 


29 


1.56 


0.53 


4.75 


2.65 


0.15 


0.85 


1.90 


0.88 


30 


2.39 


0.86 


2.59 


0.15 


1.71 


0.65 


4.94 


2.34 



*ND, not detected 



A-19 



Table A-7. Spatial variability of the inventory selenium content 
at Pond 11, Kesterson Reservoir. 



Subplot Sample Duplicate Average RPD, % 









-mg kg"^ 












lA] 


4.05 


4.54 


4.30 


11.41 


IBi 


5.52 


5.35 


5.44 


3.13 


IC] 


4.90 


4.90 


4.90 


0.00 


ID] 


2.48 


2.40 


2.44 


3.28 


IE] 


; 6.12 


6.49 


6.31 


5.87 


2A] 


7.70 


7.83 


7.77 


1.67 


2B] 


5.51 


5.56 


5.54 


0.90 


2C] 


4.78 


4.53 


4.66 


5.37 


2D] 


6.15 


5.65 


5.90 


8.47 


2E] 


5.58 


5.47 


5.53 


1.99 


3A] 


4.03 


4.16 


4.10 


3.17 


3B] 


6.27 


5.96 


6.12 


5.07 


3C] 


8.75 


8.50 


8.63 


2.90 


3D] 


L 5.01 


5.24 


5.13 


4.49 


3E] 


6.25 


6.75 


6.50 


7.69 


4A] 


3.70 


3.79 


3.75 


2.40 


4B] 


4.91 


4.64 


4.78 


5.65 


4C- 


3.96 


3.97 


3.97 


0.25 


40^ 


[ 3.73 


3.67 


3.70 


1.62 


4E] 


2.55 


2.84 


2.70 


10.76 


5A] 


L 2.51 


2.38 


2.45 


5.32 


5B] 


L 3.10 


3.28 


3.19 


5.64 


5C] 


L 4.53 


4.25 


4.39 


6.38 


5D] 


L 4.90 


2.86 


4.88 


0.82 


5E] 


L 4.10 


4.01 


4.06 


2.22 


6A] 


L 2.60 


2.57 


2.59 


1.16 


6B] 


L 4.04 


3.48 


3.76 


14.89 


6C] 


3.66 


3.27 


3.47 


11.26 


6D] 


L 3.07 


3.01 


3.04 


1.97 


6E] 


L 3.45 


3.78 


3.62 


9.13 


7A] 


[ 3.25 


3.70 


3.48 


12.95 


7B] 


[ 3.89 


3.61 


3.75 


7.47 


7Ci 


L 4.27 


4.20 


4.24 


1.65 


70^ 


[ 4.73 


4.54 


4.64 


4.10 


7E] 


L 2.44 


2.29 


2.37 


6.34 



Table A-7. 


(continued) 








Subplot 


Sample 


Duplicate 


Average 


RPD, % 






_^__^__^__rnn 


kg-^ 








■"■"""■■-■■"■" "1 11 y 




8Ai 


2.37 


2.14 


2.26 


10.20 


8Bi 


2.94 


3.26 


3.10 


10.32 


8Ci 


4.67 


4.78 


4.73 


2.33 


BDi 


5.83 


5.68 


5.76 


2.61 


SEi 


6.08 


5.61 


5.85 


8.04 


9Ai 


4.45 


4.31 


4.38 


3.20 


9Bi 


3.63 


3.40 


3.52 


6.54 


9Ci 


2.49 


2.45 


2.47 


1.62 


9Di 


3.65 


3.58 


3.62 


1.94 


9Ei 


2.34 


2.18 


2.26 


7.08 


lOAi 


4.40 


4.60 


4.50 


4.44 


lOBi 


4.43 


4.32 


4.38 


2.51 


lOCi 


3.27 


3.39 


3.33 


3.60 


lOOi 


4.92 


4.47 


4.70 


9.58 


lOEi 


3.94 


3.79 


3.87 


3.88 


llAi 


3.88 


3.92 


3.90 


1.03 


UBi 


3.68 


3.89 


3.79 


5.55 


llCi 


1.79 


1.86 


1.83 


3.84 


llDi 


3.94 


3.79 


3.87 


3.88 


llEi 


4.51 


4.47 


4.49 


0.89 


12Ai 


5.75 


6.08 


5.92 


5.58 


12Bi 


4.37 


4.39 


4.38 


0.46 


12Ci 


5.46 


5.87 


5.67 


7.24 


12Di 


4.85 


5.09 


4.97 


4.83 


12Ei 


6.03 


6.30 


6.17 


4.38 


13Ai 


3.38 


3.16 


3.27 


6.73 


13Bi 


3.04 


2.94 


2.99 


3.34 


13Ci 


3.67 


3.54 


3.61 


3.61 


13Di 


2.87 


3.10 


2.99 


7.71 


13Ei 


6.11 


6.19 


6.15 


1.30 


14Ai 


3.71 


3.69 


3.70 


0.54 


14Bi 


3.45 


3.69 


3.57 


6.72 


14Ci 


3.04 


2.94 


2.99 


3.34 


14Di 


5.29 


5.46 


5.38 


3.16 


14Ei 


4.49 


4.10 


4.30 


9.08 


15Ai 


3.60 


3.60 


3.60 


0.00 


15Bi 


6.65 


6.54 


6.60 


1.67 


15Ci 


3.48 


3.45 


3.47 


0.87 


15Di 


6.22 


6.19 


6.21 


0.48 


15Ei 


5.09 


4.91 


5.00 


3.60 



A-21 



Table A-7. 


(continued) 








Subplot 


Sample 


Dupl icate 


Average 


RPD, % 






- — — — — ••..-»— mn 


kg-^ ■ 








■"■"""■•"■"■■"•"Miy 




I6A1 


4.03 


4.02 


4.03 


0.25 


I6B1 


7.21 


7.16 


7.19 


0.70 


I6C1 


3.06 


2.96 


3.01 


3.32 


I6D1 


5.10 


5.24 


5.17 


2.71 


I6E1 


3.98 


3.88 


3.93 


2.54 


17Ai 


4.74 


4.56 


4.65 


3.87 


17Bi 


2.69 


2.66 


2.68 


1.12 


17Ci 


3.59 


3.66 


3.63 


1.93 


17Di 


3.07 


3.11 


3.09 


1.29 


17Ei 


3.49 


3.51 


3.50 


0.57 


I8A1 


3.31 


2.98 


3.15 


10.49 


I8B1 


3.85 


3.66 


3.76 


5.06 


I8C1 


3.21 


3.52 


3.37 


9.21 


I8D1 


3.62 


3.51 


3.57 


3.09 


I8E1 


3.59 


3.76 


3.68 


4.63 


19Ai 


3.46 


3.27 


3.37 


5.65 


19Bi 


2.66 


2.84 


2.75 


6.55 


19Ci 


3.00 


2.92 


2.96 


2.70 


19Di 


2.56 


2.86 


2.71 


11.07 


19Ei 


1.77 


1.64 


1.71 


7.62 


2OA1 


4.74 


4.80 


4.77 


1.26 


2OB1 


3.43 


3.33 


3.38 


2.96 


2OC1 


3.13 


3.24 


3.19 


3.45 


2OD1 


3.60 


3.82 


3.71 


5.93 


2OE1 


2.58 


2.05 


2.32 


22.89 


2IA1 


3.74 


3.20 


3.47 


15.56 


21Bx 


3.82 


-- 


— 


— 


2IC1 


6.60 


6.54 


6.57 


0.91 


2IO1 


3.74 


— 


— 


— 


2IE1 


3.77 


— 


~ 


-- 


22Ai 


4.29 


4.60 


4.45 


6.97 


22Bi 


5.79 


5.66 


5.73 


2.27 


22Ci 


3.73 


3.73 


3.73 


0.00 


22Di 


4.30 


4.32 


4.31 


0.46 


22Ei 


3.71 


3.62 


3.67 


2.46 


23Ai 


5.17 


4.88 


5.03 


5.77 


23Bi 


5.04 


4.65 


4.85 


8.05 


23Ci 


2.90 


3.05 


2.98 


5.04 


23Di 


2.60 


2.60 


2.60 


0.00 


23Ei 


3.23 


3.26 


3.25 


0.92 



Tab 


le A-7. (continued) 








Subplot Sample 


Dupl icate 


Average 


RPD, % 






■ *«M«.MMM«>*«mn 


kg-^ 








■""""•■"""""" "■iJiy 




24A- 


I 3.08 


3.11 


3.10 


0.97 


24B 


L 3.23 


3.22 


3.23 


0.31 


24C 


L 3.37 


3.73 


3.55 


10.14 


24D- 


L 4.04 


4.09 


4.07 


1.23 


24E^ 


L 5.43 


5.54 


5.49 


2.01 


25A] 


L 2.27 


2.16 


2.22 


4.97 


25B] 


L 3.15 


3,24 


3.20 


2.82 


25C 


[ 3.44 


3.31 


3.38 


3.85 


25Di 


L 4.93 


5.06 


5.00 


2.60 


25E] 


L 4.55 


4.69 


4.62 


3.03 


26A] 


[ 4.31 


4.13 


4.22 


4.27 


26B] 


[ 3.94 


3.73 


3.84 


5.48 


26C] 


L 3.85 


3.96 


3.91 


2.82 


26D] 


[ 4.15 


3.90 


4.03 


6.21 


26E] 


[ 3.73 


3.99 


3.86 


6.74 


27A] 


[ 2.79 


.— « 


^MB 


^^ 


278] 


3.31 


-- 


--. 


• - 


27C] 


2.06 


2.02 


2.04 


1.96 


27D- 


; 4.18 


__ 


_— 


__ 


27E] 


1.06 


ND 


— 


— 


28A] 


3.87 


3.70 


3.79 


4.49 


28B] 


2.19 


1.98 


2.09 


10.07 


28C] 


L 4.08 


4.22 


4.15 


3.37 


28D] 


[ 4.11 


-- 


..- 


— 


28E] 


[ 3.79 


3.74 


3.77 


1.33 


29A] 


3.75 


3.32 


3.54 


12.16 


29B] 


2.23 


2.24 


2.24 


0.45 


29C] 


3.45 


3.70 


3.58 


6.99 


29D] 


[ 3.08 


3.08 


3.08 


0.00 


29E] 


6.20 


— 


~ 


— 


30A] 


3.29 


3.26 


3.28 


0.92 


30B] 


2.86 


2.94 


2.90 


2.76 


30C] 


4.52 


4.72 


4.62 


4.33 


30D] 


[ 3.91 


— 


-- 


-- 


30E] 


4.40 


~ 


— 


— 



Table A-8. Selenium content of Kesterson sediment at Pond 11, 
September, 1987 through January, 1988. 



A-23 



Sept. 87 



Oct. 87 



Nov. 87 



Dec. 87 



Jan. 88 



— -mg kg' 



1 


5.39 


100 


5.84 


2 


6.49 


100 


) 8.33 


3 


6.33 


100 


5.65 


4 


5.70 


100 


5.58 


5 


4.89 


100 


5.16 


6 


5.22 


100 


4.89 


7 


4.11 


100 


4.85 


8 


6.18 


100 


6.12 


9 


4.78 


100^ 


5.42 


10 


3.87 


100^ 


4.20 


11 


4.47 


100 


4.06 


12 


7.67 ( 


100' 


6.33 


13 


3.73 


100' 


4.18 


14 


3.93 


100' 


4.28 


15 


4.65 ( 


100 


4.24 


16 


4.09 ( 


100' 


4.31 


17 


3.52 


100' 


3.55 


18 


3.91 ( 


100' 


3.80 


19 


3.07 ( 


100' 


2.94 


20 


4.47 ( 


100' 


4.04 


21 


4.64 ( 


100' 


4.53 


22 


3.37 


100' 


3.81 


23 


2.82 ( 


100' 


3.26 


24 


2.90 ( 


100' 


2.81 


25 


3.18 ( 


100' 


3.27 


25 


2.92 ( 


100' 


3.30 


27 


3.05 ( 


100' 


3.01 


28 


4.59 ( 


100' 


4.46 


29 


3.98 ( 


100' 


3.98 


30 


4.56 ( 


100' 


5.50 



(108. 


3) 


(128. 


.3) 


( 89. 


2) 


( 97 


9) 


(105. 


6) 


( 93. 


7) 


(118. 


0) 


( 99. 


0) 


(113. 


3) 


(108, 


6) 


( 90. 


9) 


( 82. 


8) 


(112. 


0) 


(109, 


0) 


( 91, 


1) 


(105, 


3) 


(100. 


9) 


( 97, 


1) 


( 95, 


8) 


( 90, 


3) 


( 97, 


7) 


(113, 


0) 


(115, 


7) 


( 96, 


9) 


(102, 


9) 


(113, 


0) 


( 98, 


7) 


( 97, 


1) 


(100, 


0) 


(120, 


7) 



3.92 


; 72.8) 


6.44 


; 99.2) 


5.16 


; 81.6) 


5.29 


. 92.9) 


5.01 


,102.4) 


4.97 


95.2) 


4.66 


;ii3.3) 


5.82 


. 94.1) 


4.85 


;ioi.4) 


3.87 


;ioo.o) 


4.02 


90.0) 


5.38 


70.1) 


3.45 


92.4) 


3.94 


,100.2) 


3.81 


82.0) 


4.10 


;ioo.2) 


3.71 


105.3) 


3.36 


86.0) 


2.70 ( 


88.0) 


3.78 


84.6) 


4.81 


103.7) 


3.21 


95.2) 


3.80 


124.1) 


2.45 


. 84.4) 


2.93 


. 92.1) 


2.75 


94.1) 


2.91 


95.4) 


5.00 


109.0) 


4.79 


,120.3) 


5.63 


123.4) 



4.31 
6.94 
5.24 
5.66 
5.37 
4.95 
4.81 
5.81 
5.39 
4.17 
4.15 
4.78 
3.66 
4.07 
3.82 
3.77 
3.36 
3.21 
2.90 
3.58 
4.24 
3.05 
2.97 
3.27 
2.58 
2.98 
3.19 
3.76 
4.04 
5.06 



80.0 

107.0 

82.8 

99.2 

109.9 

94.9 

117.0 

94.0 

112.8 

107.8 

92.9 

62.3 

98.1 

103.6 

82.1 

92.1 

95.4 

82.0 

94.4 

80.0 

91.3 

90.6 

105.3 

112.8 

81.1 

102.0 

104.6 

82.0 

101.6 

'111.0 



3.84 
4.98 
4.50 
4.60 
3.79 
3.71 
3.67 
5.28 
4.24 
3.14 
3.58 
3.45 
3.36 
2.92 
3.75 
3.64 
2.89 
2.49 
2.33 
3.60 
3.47 
2.84 
2.54 
2.52 
2.88 
2.51 
2.38 
3.97 
3.82 
4.49 



( 71, 


2) 


( 76, 


8) 


( 71, 


0) 


( 80, 


8) 


( 77, 


6) 


( 71, 


0) 


( 89, 


2) 


( 85, 


4) 


( 88, 


8) 


( 81. 


1) 


( 80, 


0) 


( 45, 


0) 


( 90, 


0) 


( 74, 


3) 


( 80, 


7) 


( 89. 


0) 


( 82. 


1) 


( 63. 


7) 


( 75. 


9) 


( 80. 


6) 


( 74. 


8) 


( 84. 


2) 


( 90. 


0) 


( 86. 


.9) 


( 90 


.6) 


( 86. 


0) 


( 78. 


.0) 


( 86. 


4) 


( 96 


.0) 


( 98. 


4) 



*Figures in parentheses represent percentage of selenium content remaining after 
the specified time period. 



Table A-8. Selenium content of Kesterson sediment at Pond 11, 
March, 1988 through June, 1988. 



Subplot 
no. 



Mar. 87 



Apr. 87 



May 87 



Jun.87 



mg kg 



-1 



1 


4.27 


2 


6.46 


3 


5.02 


4 


4.77 


5 


4.27 


6 


4.15 


7 


3.63 


8 


5.64 


9 


4.70 


10 


4.08 


11 


4.16 


12 


3.88 


13 


3.49 


14 


3.65 


15 


4.19 


16 


3.79 


17 


3.20 


18 


2.96 


19 


2.74 


20 


3.96 


21 


3.99 


22 


3.27 


23 


2.98 


24 


2.61 


25 


3.47 


26 


3.13 


27 


2.72 


28 


3.37 


29 


3.37 


30 


4.16 



( 79 


.2) 


( 99 


.6) 


( 79 


.3) 


( 83 


.7) 


( 87 


3) 


( 79. 


6) 


( 88. 


.3) 


( 91 


2) 


( 98. 


3) 


(108. 


0) 


( 93. 


0) 


( 50. 


6) 


( 93. 


6) 


( 92. 


9) 


( 90. 


1) 


( 92. 


7) 


( 91. 


0) 


( 75, 


8) 


( 89. 


2) 


( 88. 


6) 


( 86. 


0) 


( 97. 


0) 


(105. 


7) 


( 90. 


0) 


(109. 


1) 


(107. 


1) 


( 89. 


1) 


( 73. 


4) 


( 84. 


7) 


( 91. 


2) 



3.84 
5.17 
4.19 
4.43 
3.62 
3.72 
3.81 
4.50 
4.06 
3.26 
3.80 
3.71 
3.24 
3.15 
3.64 
3.81 
2.51 
2.84 
2.63 
2.56 
3.68 
3.36 
3.30 
2.75 
3.89 
3.48 
3.54 
3.87 
3.89 
4.76 



( 71 


.2) 


( 79 


.7) 


( 66 


.1) 


( 77 


.8) 


( 74 


.0) 


( 71 


.2) 


( 92 


.8) 


( 72 


.9) 


( 85. 


0) 


( 84. 


2) 


( 85. 


.0) 


( 48 


.3) 


( 86. 


9) 


( 80. 


.1) 


( 78. 


2) 


( 93. 


.1) 


( 71 


3) 


( 72. 


7) 


( 85. 


7) 


( 57. 


2) 


( 79 


3) 


( 99. 


8) 


(117 


0) 


( 94. 


9) 


(122. 


3) 


(119. 


1) 


(116 


1) 


( 84. 


3) 


( 97. 


8) 


(104. 


3) 



4.81 
6.40 
5.31 
5.77 
4.58 
4.22 
4.10 
6.06 
4.52 
3.87 
4.54 
3.94 
3.48 
3.76 
4.03 
4.13 
3.23 
3.20 
2.80 
3.28 
3.90 
3.27 
2.78 
2.72 
3.24 
3.19 
2.61 
3.44 
3.63 
3.94 



( 89 


.2) 


( 98 


.7) 


( 83 


.9) 


(101 


.2) 


( 93. 


.7) 


( 80 


.9) 


( 99 


.8) 


( 98 


.0) 


( 94. 


.6) 


(100. 


0) 


(101. 


5) 


( 51. 


3) 


( 93. 


.2) 


( 95. 


7) 


( 36. 


7) 


(101. 


0) 


( 91. 


8) 


( 81 


9) 


( 91. 


2) 


( 73. 


3) 


( 84. 


0) 


( 97. 


0) 


( 98. 


6) 


( 93. 


8) 


(101. 


9) 


(109. 


2) 


( 85. 


6) 


( 75. 


0) 


( 91. 


2) 


( 86. 


4) 



3.84 
4.78 
4.30 
5.17 
4.60 
4.28 
4.25 
5.64 
4.52 
3.64 
4.49 
4.03 
3.46 
3.12 
3.85 
4.08 
3.06 
3.19 
2.96 
3.38 
3.93 
3.79 
3.07 
2.69 
3.78 
3.53 
2.56 
3.51 
3.71 
4.57 



( 71 


.2) 


( 73. 


.7) 


( 68 


.0) 


( 90 


8) 


( 94. 


0) 


( 82 


.0) 


(103 


4) 


( 91 


2) 


( 94. 


6) 


( 94 


0) 


(100. 


4) 


( 52 


6) 


( 92 


8) 


( 79. 


3) 


( 82. 


8) 


( 99. 


8) 


( 87. 


0) 


( 81. 


6) 


( 96. 


4) 


( 75. 


7) 


( 84. 


7) 


(112. 


4) 


(108. 


9) 


( 92. 


8) 


(118. 


9) 


(120. 


9) 


( 84. 


0) 


( 76. 


4) 


( 93. 


2) 


(100. 


2) 



A-25 



Table A-8. Selenium content of Kesterson sediment at Pond 11, 
July, 1988 through August, 1988. 



Subplot 
no. 



Jul. 88 



Aug. 88 



mg kg 



-1 



1 


5.16 


2 


6.06 


3 


6.00 


4 


5.73 


5 


4.79 


6 


4.45 


7 


4.89 


8 


5.84 


9 


5.37 


10 


3.57 


11 


4.36 


12 


3.92 


13 


3.61 


14 


3.54 


15 


4.09 


16 


4.01 


17 


3.29 


18 


2.99 


19 


3.29 


20 


3.63 


21 


3.54 


22 


3.44 


23 


2.93 


24 


2.65 


25 


3.39 


26 


3.54 


27 


2.95 


28 


3.58 


29 


3.51 


30 


4.21 



95.8 
93.3 
94.8 

100.6 
98.0 
85.2 

119.0 
94.4 

112.3 
92.2 
97.6 
51.1 
96.8 
90.0 
88.0 
98.0 
93.4 
76.4 

107.1 
81.2 
76.2 

102.0 

104.0 
91.3 

106.7 

121.2 
96.8 
78.0 
88.1 
92.3 



3.91 
5.76 
5.38 
5.02 
4.61 
4.04 
4.05 
4.91 
4.32 
3.34 
3.94 
3.76 
3.37 
3.45 
3.50 
3.58 
2.97 
2.79 
2.51 
3.13 
3.51 
3.25 
2.75 
2.73 
3.59 
3.63 
2.69 
3.85 
3.69 
4.54 



( 72. 


5) 


( 88. 


8) 


( 85. 


0) 


( 88. 


1) 


( 94. 


3) 


( 77. 


4) 


( 98. 


5) 


( 79. 


4) 


( 90. 


4) 


( 86, 


3) 


( 88. 


1) 


( 49. 


0) 


( 90. 


3) 


( 87. 


8) 


( 75. 


3) 


( 87. 


5) 


( 84. 


4) 


{ 71 


4) 


( 81. 


8) 


( 70. 


0) 


( 75. 


6) 


( 96. 


4) 


( 97. 


5) 


( 94. 


1) 


(112. 


9) 


(124. 


3) 


( 88. 


2) 


( 83. 


9) 


( 92 


7) 


( 99. 


6) 



A-26 



Table A-9. Profile distribution of selenium at Pond 11, 
Kesterson Reservoir. 





Depth 


Selenium content (mg kg"' 


■ soil) 


Subplot 


Nov. 


1987 






(in.) 


(25) 






2 


0-6 


5.59 


(3.22) 




2 


6-12 


1.28 


(11.76) 




2 


12-18 


ND 






2 


18-24 


ND 






4 


0-6 


3.21 


(7.18) 




4 


6-12 


1.10 


(6.39) 




4 


12-18 


ND 






4 


18-24 


ND 


• 




6 


0-6 


3.94 


(7.11) 




6 


6-12 


ND 






6 


12-18 


ND 






6 


18-24 


ND 






10 


0-6 


3.24 


(6.79) 




10 


6-12 


ND 






10 


12-18 


ND 






10 


18-24 


ND 






24 


0-6 


1.60 


(1.88) 




24 


6-12 


ND 






24 


12-18 


ND 






24 


18-24 


ND 






25 


0-6 


1.56 


(2.56) 




25 


6-12 


ND 






25 


12-18 


ND 






25 


18-24 


ND 







A-27 



Table A-10. Al kyl selenide production monitored from the San Luis 
Drain sediments during the month of September, 1988. 



Subplot 
no. 9/22/87 9/26/88 9/29/88 



101 


26.9 


iiiy ^y 

152.9 


261.8 


102 


29.2 


139.6 


594.0 


103 


42.5 


127.6 


954.8 


104 


38.9 


327.5 


756.4 


105 


38.1 


247.1 


1425.2 


106 


42.3 


384.2 


1146.2 


107 


99.4 


616.8 


917.8 


108 


106.6 


694.6 


814.8 


109 


99.8 


901.4 


1308.6 


110 


18.0 


1141.8 


1374.4 


111 


20.7 


665.0 


1418.8 


112 


29.3 


767.6 


982.2 


113 


15.1 


296.6 


500.0 


114 


26.8 


248.4 


387.4 


115 


29.8 


287.0 


980.0 


116 


14.0 


475.8 


873.8 


117 


18.1 


112.0 


581.8 


118 


45.2 


340.4 


802.4 


119 


31.5 


34.2 


272.0 


120 


17.6 


59.8 


280.4 


121 


24.5 


56.0 


254.4 


122 


17.9 


224.6 


1051.0 


123 


13.8 


144.0 


810.6 


124 


30.7 


303.0 


1226.0 



A-28 

CAUFORNIA STATE UNIVERSITY ♦ FRESNO 



FRESNO, CALIFORNIA 93740-0094 

DEPARTMENT OF CIVIL ENGINEERING 
& SURVEYING ENGINEERING 

i:09) 294-2889 




October 4, 1988 



Dr. William Frankenberger 

UC Riverside 

Dept. of Soil & Environmental Sciences 

2416 Geology Bldg. 

Riverside, CA 92521 



Dear Dr. Frankenberger, 

Enclosed are the final reports of all of the Kesterson selenium 
analyses we have completed to date: 

Inventory Samples 
September 1987 Composites 
October 1987 Composites 
November 1987 Composites 
December 1987 Composites 
January 1988 Composites 
** (February 1988 no samples received) 
March 1988 Composites 
April 1988 Composites 
May 1988 Composites 
June 1988 Composites 
July 1988 Composites 

Profile July 29, 1987 
Profile November 25, 1987 
Profile January 19, 1988 
Profile July 24, 1983 
Profile July 24, 1988 

If there are any questions concerning these reports please let us know. 



Sincerely, 

/I. ■■ ^^ 

Brenda Royce, / 
Lab Supervisor 

BR:bg 
enclosures 



THE CALIFORNIA STATl UNlVERSIPr 



Project :Kesterson Selenium Study 

Date :June 2, 1988 

Sample Set : Inventory Samples, Pond 11 A-E Samples 

Received -.August 17, 1987 



A-29 



Site ID 



1 


Ai 


1 


Bl 


1 


CI 


1 


Dl 


1 


El 


2 


Al 


2 


Bl 


2 


CI 


2 


Dl 


2 


El 


3 


Al 


3 


Bl 


3 


CI 


3 


Dl 


3 


El 


4 


Al 


4 


Bl 


4 


CI 


4 


Dl 


4 


El 


5 


Al 


5 


Bl 


5 


CI 


5 


Dl 


5 


El 


6 


Al 


6 


Bl 


6 


CI 


6 


Dl 


6 


El 


7 


Al 


7 


Bl 


7 


CI 


7 


Dl 


7 


El 


8 


Al 


8 


Bl 


8 


CI 


8 


Dl 


8 


El 



Lab Number 



1.001 
1.002 
1.003 
1.004 
1.005 
1.006 
1.007 
1.008 
1.009 
1.010 
1.011 
1.012 
1.013 
1.014 
1.015 
1.016 
1.017 
1.018 
1.019 
1.020 
1.021 
1.022 
1.023 
1.024 
1.025 
1.026 
1.027 
1.028 
1.029 
1.030 
1.031 
1.032 
1.033 
1.034 
1.035 
1.036 
1.037 
1.038 
1.039 
1.040 



Sample 


Dupl icate 


Average 


RPD* 


ppm 


ppm 


ppm 


■/. 


4.05 


4.54 


4.30 


11.41 


5.52 


5.35 


5.44 


3.13 


4.90 


4.90 


4.90 


0.00 


2.48 


2.40 


2.44 


3.28 


6.12 


6.49 


6.31 


5.87 


7.70 


7.83 


7.77 


1 .67 


5.51 


5.56 


5.54 


0.90 


4.78 


4.53 


4.66 


5.37 


6.15 


5.65 


5.90 


8.47 


5.58 


5.47 


5.53 


1.99 


4.03 


4.16 


4.10 


3.17 


6.27 


5.96 


6.12 


5.07 


8.75 


8.50 


8.63 


2.90 


5.01 


5.24 


5.13 


4.49 


6.25 


6.75 


6.50 


7.69 


3.70 


3.79 


3.75 


2.40 


4.91 


4.64 


4.78 


5.65 


3.96 


3.97 


3.97 


0.25 


3.73 


3.67 


3.70 


1.62 


2.55 


2.84 


2.70 


10.76 


2.51 


2.38 


2.45 


5.32 


3.10 


3.28 


3.19 


5.64 


4.53 


4.25 


4.39 


6.38 


4.90 


4.86 


4.88 


0.82 


4.10 


4.01 


4.06 


2.22 


2.60 


2.57 


2.59 


1.16 


4.04 


3.48 


3.76 


14.89 


3.66 


3.27 


3.47 


11.26 


3.07 


3.01 


3.04 


1.97 


3.45 


3.78 


3.62 


9.13 


3.25 


3.70 


3.48 


12.95 


3.89 


3.61 


3.75 


7.47 


4.27 


4.20 


4.24 


1 .65 


4.73 


4.54 


4.64 


4.10 


2.44 


2.29 


2.37 


6.34 


2.37 


2.14 


2.26 


10.20 


2.94 


3.26 


3.10 


10.32 


4.67 


4.78 


4.73 


2.33 


5.83 


5.68 


5.76 


2.61 


6.08 


5.61 


5.85 


8.04 



Project 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 

:June 2, 1988 

: Inventory Samples, Pond 11 A-E Sample; 

lAugust 17, 1987 



Page 2 



Site ID 



9 
9 
9 
9 
9 
10 
10 
10 
10 
10 
11 
11 
11 
11 
11 
12 
12 
12 
12 
12 
13 
13 
13 
13 
13 
14 
14 
14 
14 
14 
15 
15 
15 
15 
15 



Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 
Al 
Bl 
CI 
Dl 
El 



Lab Number 



1.041 
1.042 
1.043 
1.044 
1.045 
1.046 
1.047 
1.048 
1.049 
1.050 
1.051 
1.052 
1.053 
1.054 
1.055 
1.056 
1.057 
1.058 
1.059 
1.060 
1.061 
1.062 
1.063 
1.064 
1.065 
1.066 
1.067 
1.068 
1.069 
1.070 
1.071 
1.072 
1.073 
1.074 
1.075 



Sample 


Dupl icate 


Average 


ppm 


ppm 


ppm 


4.45 


4.31 


4.38 


3.63 


3.40 


3.52 


2.49 


2.45 


2.47 


3.65 


3.58 


3.62 


2.34 


2.18 


2.26 


4.40 


4.60 


4.50 


4.43 


4.32 


4.38 


3.27 


3.39 


3.33 


4.92 


4.47 


4.70 


3.94 


3.79 


3.87 


3.88 


3.92 


3.90 


3.68 


3.89 


3.79 


1.79 


1 .86 


1.83 


3.94 


3.79 


3.87 


4.51 


4.47 


4.49 


5.75 


6.08 


5.92 


4.37 


4.39 


4.38 


5.46 


5.87 


5.67 


4.85 


5.09 


4.97 


6.03 


6.30 


6.17 


3.38 


3.16 


3.27 


3.04 


2.94 


2.99 


3.67 


3.54 


3.61 


2.87 


3.10 


2.99 


6.11 


6.19 


6.15 


3.71 


3.69 


3.70 


3.45 


3.69 


3.57 


3.04 


2.94 


2.99 


5.29 


5.46 


5.38 


4.49 


4.10 


4.30 


3.60 


3.60 


3.60 


6.65 


6.54 


6.60 


3.48 


3.45 


3.47 


6.22 


6. 19 


6.21 


5.09 


4.91 


5.00 



RPD* 



3, 

6, 

1 , 

1 , 

7, 

4, 

2, 

3, 

9, 

3, 

1, 

5, 

3 

3, 



5, 



1 . 

4 

4, 

6, 

3, 

3 

7, 

1, 

0, 

6, 

3, 

3, 

9, 

0, 

1 , 

0, 

0, 

3, 



20 
54 
62 
94 
08 
44 
51 
60 
58 
88 
03 
55 
84 
88 
89 
58 
46 
24 
83 
38 
73 
34 
61 
71 
30 
54 
72 
34 
16 
08 
00 
67 
87 
48 
60 



A-31 



Project 


: Kesterson 


Selenium 


Study 




Page 3 


Date 


:June 2, 1988 








Sample Se 


t : Inventory 


Samples, 


Pond 11 A-E 


Samples 




Received 


: August 17, 


1987 








Site ID 


Lab Number 


Sample 


Dupl icate 


Average 


RPD* 






ppm 


ppm 


ppm 


•/. 


16 Al 


1.076 


4.03 


4.02 


4.03 


0.25 


16 Bl 


1.077 


7.21 


7.16 


7.19 


0.70 


16 Ci 


1.078 


3.06 


2.96 


3.01 


3.32 


16 Dl 


1.079 


5.10 


5.24 


5.17 


2.71 


16 El 


1.080 


3.98 


3.88 


3.93 


2.54 


17 Ai 


1.081 


4.74 


4.56 


4.65 


3.87 


17 Bl 


1.082 


2.69 


2.66 


2.68 


1.12 


17 CI 


1.083 


3.59 


3.66 


3.63 


1.93 


17 Dl 


1.084 


3.07 


3.11 


3.09 


1.29 


17 El 


1.085 


3.49 


3.51 


3.50 


0.57 


18 Al 


1.086 


3.31 


2.98 


3.15 


10.49 


18 Bl 


1.087 


3.85 


3.66 


3.76 


5.06 


18 CI 


1.088 


3.21 


3.52 


3.37 


9.21 


18 Dl 


1.089 


3.62 


3.51 


3.57 


3.09 


18 El 


1.090 


3.59 


3.76 


3.68 


4.63 


19 Al 


1.091 


3.46 


3.27 


3.37 


5.65 


19 Bl 


1.092 


2.66 


2.84 


2.75 


6.55 


19 CI 


1.093 


3.00 


2.92 


2.96 


2.70 


19 Dl 


1.094 


2.56 


2.86 


2.71 


11.07 


19 El 


1.095 


1.77 


1.64 


1.71 


7.62 


20 Al 


1.096 


4.74 


4.80 


4.77 


1.26 


20 Bl 


1.097 


3.43 


3.33 


3.38 


2.96 


20 CI 


1.098 


3.13 


3.24 


3.19 


3.45 


20 Dl 


1.099 


3.60 


3.82 


3.71 


5.93 


20 El 


1.100 


2.58 


2-05 


2.32 


22.89 


21 Al 


1.101 


3.74 


3.20 


3.47 


15.56 


21 Bl 


1.102 


3.82 











21 CI 


1.103 


6.60 


6.54 


6.57 


0.91 


21 Dl 


1.104 


3.74 











21 El 


1.105 


3.77 











22 Al 


1.106 


4.29 


4.60 


4.45 


6.97 


22 Bl 


1.107 


5.79 


5.66 


5.73 


2.27 


22 CI 


1.108 


3.73 


3.73 


3.73 


0.00 


22 Dl 


1.109 


4.30 


4.32 


4.31 


0.46 


22 El 


1 . 110 


3.71 


3.62 


3.67 


2.46 


23 A4 


1.111 


5.17 


4.88 


5.03 


5.77 


23 B4 


1.112 


5.04 


4.65 


4.85 


8.05 


23 C4 


1.113 


2.90 


3.05 


2.98 


5.04 


23 D4 


1.114 


2.60 


2.60 


2.60 


0.00 


23 E4 


1.115 


3.23 


3.26 


3.25 


0.92 



A-32 



Project 


Date 


Sam| 


Die Set 


Received 


Site ID 


24 


Ai 


24 


Bl 


24 


CI 


24 


Dl 


24 


El 


25 


Ai 


25 


Bi 


25 


Ci 


25 


Di 


25 


Ei 


26 


Ai 


26 


Bl 


26 


Ci 


26 


Di 


26 


El 


27 


Ai 


27 


Bl 


27 


Ci 


27 


Di 


27 


El 


28 


Ai 


28 


Bi 


28 


Ci 


28 


Di 


28 


El 


29 


Ai 


29 


Bl 


29 


CI 


29 


Dl 


29 


Ei 


30 


AI 


30 


Bl 


30 


Ci 


30 


Dl 


30 


El 



iKesterson Selenium Study 

;June 2, 1988 

1 Inventory Samples, Pond 11 A-E Samples 

;August 17, 1987 



Lab Number 



Page 4 



1 


. 116 


i 


.117 


1 


.118 


1 


.119 


1 


.120 


1, 


.121 


1 


.122 


1 , 


.123 


1 , 


.124 


1 , 


.125 


1 , 


.126 


1, 


.127 


i, 


.128 


1 , 


.129 


1, 


.130 


1, 


.131 


1 , 


.132 


1. 


.133 


1, 


.134 


1, 


.135 


1 , 


. 136 


1. 


.137 


1. 


.138 


1. 


,139 


1 , 


.140 


1. 


,141 


1 . 


,142 


1. 


,143 


1. 


,144 


1 . 


,145 


1 . 


,146 


1 . 


,147 


1 . 


,148 


1. 


, 149 


1. 


,150 



Sample 


Dupl icate 


Average 


RPD* 


ppm 


ppm 


ppm 


7. 


3.08 


3. 11 


3.10 


0.97 


3.23 


3.22 


3.23 


0.31 


3.37 


3.73 


3.55 


10.14 


4.04 


4,09 


4.07 


1.23 


5.43 


5.54 


5.49 


2.01 


2.27 


2. 16 


2.22 


4.97 


3.15 


3.24 


3.20 


2.82 


3.44 


3.31 


3.38 


3.85 


4.93 


5.06 


5.00 


2.60 


4.55 


4.69 


4.62 


3.03 


4.31 


4.13 


4.22 


4.27 


3.94 


3.73 


3.84 


5.48 


3.85 


3.96 


3.91 


2.82 


4.15 


3.90 


4.03 


6.21 


3.73 


3.99 


3.86 


6.74 


2.79 











3.31 











2.06 


2.02 


2.04 


1.96 


4.18 


• ^^^ 








1.06 


ND 








3.87 


3.70 


3.79 


4.49 


2.19 


1.98 


2.09 


10.07 


4.08 


4.22 


4.15 


3.37 


4.11 











3.79 


3.74 


3.77 


1.33 


3.75 


3.32 


3.54 


12.16 


2.23 


2.24 


2.24 


0.45 


3.45 


3.70 


3.58 


6.99 


3.08 


3.08 


3.08 


0.00 


6.20 











3.29 


3.26 


3.28 


0.92 


2.86 


2.94 


2.90 


2.76 


4.52 


4.72 


4.62 


4.33 


3.91 











4.40 












A-33 



Project 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 

:March 3, 1988 

: Inventory Samples, Pond 4 A-E Sample? 

:August 17, 1987 



Site ID 



Lab Number 



51 


Al 


51 


Bi 


51 


CI 


51 


Dl 


51 


El 


52 


Al 


52 


Bl 


52 


CI 


52 


Dl 


52 


El 


53 


Al 


53 


Bl 


53 


CI 


53 


Dl 


53 


El 


54 


Al 


54 


Bl 


54 


CI 


54 


Dl 


54 


El 


55 


Al 


55 


Bl 


55 


CI 


55 


Dl 


55 


El 


56 


Al 


56 


Bl 


56 


CI 


56 


Dl 


56 


El 


57 


Al 


57 


Bl 


57 


CI 


57 


Dl 


57 


El 


58 


Al 


58 


Bl 


58 


CI 


58 


Dl 


58 


El 



1 

1 

1 

1 

1 

1, 

1 

1, 

1 

1, 

1 , 

1, 

1, 

1, 

1 , 

1, 

1, 

1 , 

1 , 

1, 

1, 

1 , 

1, 

1. 

1, 

1 . 

1. 

1 . 

1, 

1. 

1 . 

1 . 

1. 

1. 

1 . 

1. 

1. 

1. 

1. 

1. 



151 
152 
153 
154 
155 
156 
157 
158 
159 
160 
161 
162 
163 
164 
165 
166 
167 
168 
169 
170 
171 
172 
173 
174 
175 
176 
177 
178 
179 
180 
181 
182 
183 
184 
185 
186 
187 
188 
189 
190 



Sample 


Dupl icate 


Average 


ppm 


ppm 


ppm 


37.95 


37.89 


37.92 


37.00 


36. 11 


36.56 


33.25 


37.77 


35.51 


9.92 


10.09 


10.01 


21.89 


21.79 


21.84 


35.65 


34.93 


35.29 


123.49 


124.84 


124.17 


60.20 


58.58 


59.39 


75.02 


74.02 


74.52 


60.56 


64.32 


62.44 


36.07 


37.89 


36.98 


42.79 


44.14 


43.47 


36.29 


36.48 


36.39 


35.75 


35.80 


35.78 


37.92 


38.61 


38.27 


29.23 


28.75 


28.99 


27.26 


26.78 


27.02 


25.87 


26.02 


25.95 


30.97 


29.97 


30.47 


28.37 


30.32 


29.35 


88.98 


86.59 


87.79 


61 .48 


61.50 


61.49 


132.37 


133.59 


132.98 


104.28 


100.40 


102.34 


28.70 


29.38 


29.04 


117.01 


106.33 


111 .67 


37.44 


39.19 


38.32 


81.37 


81.95 


81.66 


210.89 


206.92 


208.91 


76.96 


74.32 


75.64 


136.37 


133.73 


135.05 


41.64 


40.75 


41.20 


75.90 


72.99 


74.45 


34.10 


34.23 


34.17 


47.42 


48.99 


48.21 


18.51 


18.87 


18.69 


35.26 


33.80 


34.53 


42.81 


46.28 


44.55 


66.35 


71.95 


69.15 


25.17 


24.04 


24.61 



RPD* 
■/. 

0. 16 

2.43 

12.73 



0, 
3, 
2. 
9. 
4. 
0. 
1. 
3. 
1 . 
2. 
3. 
0. 
3. 
1 . 
4. 
7. 



,70 
,46 
,04 
,09 
,73 
,34 
,02 
,92 
,11 
,52 



0.15 



,80 
,66 
,78 
,58 
28 
65 
,72 



0.03 



92 
79 
34 
56 
57 
71 
90 
49 
95 
16 
91 
38 
26 
93 
23 
79 



8.10 
4.59 



Project 


: Kesterson 


Selenium 


Study 




Page 2 


Date 


:March 3, 


1988 








Sam; 


Die Set 


: Inven tory 


Samples , 


Pond 4 A-E 


Samples 




Received 


:August 17 


, 1987 








Site ID L. 


ab Number 


Sample 


Dupl icate 


Average 


RPD* 








ppm 


ppm 


ppm 


■/. 


59 


Al 


1.191 


22.58 


22.44 


22.51 


0.62 


59 


Bl 


1.192 


31.52 


32.50 


32.01 


3.06 


59 


CI 


1.193 


22.03 


21.90 


21.97 


0.59 


59 


Dl 


1.194 


37.96 


36.58 


37.27 


3.70 


59 


El 


1.195 


68.54 


69.39 


68.97 


1.23 


60 


Al 


1.196 


24.29 


24.08 


24.19 


0.87 


60 


Bl 


1.197 


47.64 


43.60 


45.62 


8.86 


60 


CI 


1.198 


18.23 


17.54 


17.89 


3.86 


60 


Dl 


1.199 


22.13 


20.48 


21.31 


7.74 


60 


El 


1.200 


38.72 


37.93 


38.33 


2.06 


61 


Al 


1.201 


49.72 


48.02 


48.87 


3.48 


61 


Bl 


1.202 


40.55 


39.68 


40,12 


2.17 


61 


CI 


1.203 


19.14 


18.97 


19.06 


0.89 


61 


Dl 


1.204 


39.87 


37.81 


38.84 


5.30 


61 


El 


1.205 


61.20 


63.28 


62.24 


3.34 


62 


Al 


1.206 


66.52 


68.88 


67.70 


3.49 


62 


Bl 


1.207 


44.80 


42.86 


43.83 


4.43 


62 


CI 


1.208 


59.49 


58.94 


59.22 


0.93 


62 


Dl 


1.209 


37.84 


38.16 


38.00 


0.84 


62 


El 


1.210 


50.51 


51.10 


50.81 


1 . 16 


63 


Al 


1.211 


61 . 55 


62.25 


61 .90 


1 . 13 


63 


Bl 


1.212 


61.91 


62.86 


62.39 


1.52 


63 


CI 


1.213 


33.97 


34.41 


34.19 


1.29 


63 


Dl 


1.214 


15.58 


16.12 


15.85 


3.41 


63 


El 


1.215 


32.50 


35.22 


33.86 


8.03 


64 


Al 


1.216 


50.64 


50.10 


50.37 


1.07 


64 


Bl 


1.217 


125.95 


127.49 


126.72 


1.22 


64 


Ci 


1.218 


52.47 


54.44 


53.46 


3.69 


64 


Dl 


1.219 


48.74 


49.82 


49.28 


2.19 


64 


El 


1.220 


18.69 


19.22 


18.96 


2.80 


65 


Al 


1.221 


51.41 


51.68 


51.55 


0.52 


65 


Bl 


1.222 


74.22 


72.48 


73.35 


2.37 


65 


CI 


1.223 


62.63 


64.67 


63.65 


3.21 


65 


Dl 


1.224 


39.47 


40.10 


39.79 


1.58 


65 


El 


1.225 


46.51 


43.45 


44.98 


6.80 


66 


Al 


1.226 


32.57 


33.07 


32.82 


1.52 


66 


Bl 


1.227 


28.38 


29.08 


28.73 


2.44 


66 


CI 


1.228 


33.91 


33.70 


33.81 


0.62 


66 


Dl 


1.229 


23.52 


25.61 


24.57 


8.51 


66 


El 


1.230 


24.43 


22.54 


23.49 


8.05 



A-35 



Project :Kesterson Selenium Study 

Date :July 5, 1988 

Sample Set iSeptember 1987 Samples, Composites 

Received :December 18, 1987 



Site ID Lab Number 



Pond 11 






1 


8.001 


-8.0O5 


2 


8.006 


-8.010 


3 


8.011 


-8.015 


4 


8.016 


-8.020 


5 


8.021 


-8.025 


6 


8.026 


-8.030 


7 


8.031 


-8.035 


8 


8.036 


-8.040 


9 


8.041 


-8.045 


10 


8.046 


-8.050 


11 


8.051 


-8.055 


12 


8.056 


-8.060 


13 


8.061 


-8.065 


14 


8.066 


-8.070 


15 


8.071 


-8.075 


16 


8.076 


-8.080 


17 


8.081 


-8.085 


18 


8.086 


-8.090 


19 


8.091 


-8.095 


20 


8.096 


-8.100 


21 


. 8.101 


-8.105 


22 


8.106 


-8.110 


23 


8.111 


-8.115 


24 


8.116 


-8.120 


25 


8.121 


-8.125 


26 


8.126 


-8.130 


27 


8.131 


-8.135 


28 


8.136 


-8.140 


29 


8.141 


-8.145 


30 


8.146 


-8.150 



Sample 


Duplicate 


RPD 


ppm 


ppm 


7. 


5.39 






6.49 






6.33 






5.70 






4.89 


5.04 


3. 


5.22 






4.11 






6.18 






4.76 






3.87 






4.47 






7.67 






3.73 






3.93 






4.65 






4.09 






3.52 






3.91 






3.07 






4.47 






4.64 






3.37 






2.82 






2.90 






3.18 






2.92 


2.81 


3. 


3.05 






4.59 






3.98 







4.56 



A-36 



Project :Kesterson Selenium Study 

Date :July 5, 1988 

Sample Set :September 1987 Samples, Composites 

Received :December 18, 1987 



Site 
Pond 



ID 


Lab Number 


Sample 


Oupl icate 


RPD 








ppm 


ppm 


7. 


4 












51 


8. 151 


-8.155 


27.10 






52 


8. 156 


-8.160 


50.50 






53 


8.161 


-8.165 


57.67 






54 


8. 166 


-8.170 


39.97 






55 


8.171 


-8.175 


68.16 






56 


8.176 


-8.180 


81.62 






57 


8. 181 


-8.185 


54.28 






58 


8.186 


-8.190 


35.72 






59 


8.191 


-8.195 


31.73 






60 


8.196 


-8.200 


35.47 


36.77 


3.. 


61 


8.201 


-8.205 


52.17 






62 


8.206 


-8.210 


71.69 






63 


8.211 


-8.215 


78.88 






64 


8.216 


-8.220 


65.35 






65 


8.221 


-8.225 


83.16 







60 



66 8.226 -8.230 34.16 



«RPD = Relative Percent Difference: [2* ( A-B ) / ( A+B ) ] «100y. 



A-37 



Project :Kesterson Selenium Study 

Date :July 20, 1988 

Sample Set :October 1987 Samples, Composites 

Received :October 1987 



Site ID Lab Number Sample Duplicate RPD 

ppm ppm 7. 



Pond 



11 






1 


3.001 


-3.0O5 


2 


3.006 


-3.010 


3 


3.011 


-3.015 


4 


3.016 


-3.020 


5 


3.021 


-3.025 


6 


3.026 


-3.030 


7 


3.031 


-3.035 


8 


3.036 


-3.040 


9 


3.041 


-3.045 


10 


3.046 


-3.050 


11 


3.051 


-3.055 


12 


3.056 


-3.060 


13 


3.061 


-3.065 


14 


3.066 


-3.070 


15 


3.071 


-3.075 


16 


3.076 


-3.080 


17 


3.081 


-3.085 


18 


3.086 


-3.090 


19 


3.091 


-3.095 


20 


3.096 


-3.100 


21 


3.101 


-3.105 


22 


3. 106 


-3.110 


23 


3.111 


-3.115 


24 


3. 116 


-3.120 


25 


3.121 


-3.125 


26 


3.126 


-3.130 


27 


3.131 


-3.135 


28 


3.136 


-3.140 


29 


3.141 


-3.145 


30 


3.146 


-3.150 



5.84 

8.33 

5.65 

5.58 

5.16 

4.89 

4.85 4.75 2.08 

6.12 

5.42 

4.20 

4.06 

6.35 

4.18 

4.28 

4.24 

4.31 4.30 0.23 

3.55 

3.80 

2.94 

4.04 

4.53 

3.81 3.68 3.47 

3.26 

2.81 

3.27 

3.30 

3.01 

4.46 

3.98 

5.50 



A-38 



Project 


:Kest 


erson Sel 


enium Study 




Date 


: July 


20, 1988 






Sample Set 


:0c to 


ber 1987 


Samples, Com 


posi tes 


Received 


:Qcto 


ber 19S7 






Site ID 


Lab Number 


Sample D 


upl icate 








ppm 


ppm 


Pond 4 










51 


3.151 


-3.151 


20.25 


23.07 


52 


3.156 


-3.156 


50.63 




53 


3.161 


-3.161 


48.42 




54 


3.166 


-3.166 


36.02 




55 


3.171 


-3.171 


65.44 




56 


3.176 


-3.176 


71.40 




57 


3.181 


-3.181 


58.67 




58 


3.186 


-3.186 


35.04 




59 


3.191 


-3.191 


32.68 




60 


3.196 


-3.196 


33.45 




61 


3.201 


-3.201 


46.41 




62 


3.206 


-3.206 


52.44 


53.66 


63 


3.211 


-3.211 


58.01 




64 


3.216 


-3.216 


40.75 




65 


3.221 


-3.221 


48.83 




66 


3.226 


-3.226 


29.52 





RPD 



13.02 



2.30 



«RPD = Relative Percent Difference: [2* ( A-B ) / ( A+B ) ] *1007. 



A-39 



Project 


:Kest 


:erson Sell 


enium Stu 


dy 






Date 


: July 


• 1, 1988 










Sample Set 


: November 1987 


Samples, 


Com 


posites 




Received 


: December 1, 1987 








Site ID 


Lab Number 


Sample 


Dup 


licate 


RPD 








ppm 




ppm 


•/. 


Pond 4 














51 


7.151 


-7,155 


20.17 




20.35 


0.89 


52 


7.156 


-7.160 


55.82 








53 


7.161 


-7.165 


50.12 








54 


7.166 


-7.170 


39.60 








55 


7.171 


-7.175 


80.77 








56 


7.176 


-7.180 


85.94 








57 


7.181 


-7.185 


71.59 








58 


7.186 


-7.190 


35.95 








59 


7.191 


-7.195 


33.67 








60 


7.196 


-7.200 


34.33 








61 


7.201 


-7.205 


54.34 








62 


7.206 


-7.210 


66.00 








63 


7.211 


-7.215 


60.71 








64 


7.216 


-7.220 


46.87 








65 


7.221 


-7.225 


56.40 








66 


7.226 


-7.230 


36.20 









A-40 



Project 


iKesterson Sell 


=nium Study 






Date 


:July 1, 1988 








Sample Set 


: November 1987 


Samples, Com 


posites 




Received 


:December 1, 1987 






Site ID 


Lab Number 


Sample Dup 


licate 


RPD 








ppm 


ppm 


7. 


Pond 11 












1 


7.001 


-7.005 


3.92 






2 


7.006 


-7.010 


6.44 






3 


7.011 


-7.015 


5.16 






4 


7.016 


-7.020 


5.29 






5 


7.021 


-7.025 


5.01 






6 


7.026 


-7.030 


4.97 






7 


7.031 


-7.035 


4.66 






a 


7.036 


-7.040 


5.82 






9 


7.041 


-7.045 


4.85 






10 


7.046 


-7.050 


3.87 






11 


7.051 


-7.055 


4.02 






12 


7.056 


-7.060 


5.38 






13 


7.061 


-7.065 


3.45 






14 


7.066 


-7.070 


3.94 






15 


7.071 


-7.075 


3.81 






16 


7.076 


-7.080 


4.10 






17 


7.081 


-7.085 


3.71 






18 


7.086 


-7.090 


3.36 


3.06 


9.35 


19 


7.091 


-7.095 


2.70 






20 


7.096 


-7.100 


3.78 






21 


7.101 


-7.105 


4.81 






22 


7. 106 


-7.110 


3.21 






23 


7.111 


-7.115 


3.50 






24 


7. 116 


-7.120 


2.45 






25 


7.121 


-7.125 


2.93 






26 


7.126 


-7.130 


2.75 






27 


7.131 


-7.135 


2.91 


2.91 


0.00 


28 


7.136 


-7.140 


5.00 


4.75 


5.13 


29 


7.141 


-7.145 


4.79 






30 


7.146 


-7.150 


5.63 







A-41 



Project 


:Kesterson Sel 


enium Stu 


dy 




Date 


-.July 1, 1988 








Sample Set 


: December 1987 


Samples , 


Composites 




Received 


: November 30, 


1987 






Site ID 


Lab Number 


Sample 


Dupl icate 


RPD 








ppm 


ppm 


•/. 


Pond 11 












1 


6.001 


-6.005 


4.31 






2 


6.006 


-6.010 


6.94 






3 


6.011 


-6.015 


5.24 






4 


6.016 


-6.020 


5.66 






5 


6.021 


-6.025 


5.37 






6 


6.026 


-6.030 


4.95 






7 


6.031 


-6.035 


4.81 






8 


6.036 


-6.040 


5.81 






9 


6.041 


-6.045 


5.39 






10 


6.046 


-6.050 


4.17 






11 


6.051 


-6.055 


4.15 






12 


6.056 


-6.060 


4.78 






13 


6.061 


-6.065 


3.66 






14 


6.066 


-6.070 


4.07 






15 


6.071 


-6.075 


3.82 






16 


6.076 


-6.080 


3.77 






17 


6.081 


-6.085 


3.36 






18 


6.086 


-6.090 


3.21 






19 


6.091 


-6.095 


2.90 






20 


6.096 


-6.100 


3.58 






21 


6.101 


-6.105 


4.24 






22 


6.106 


-6. 110 


3.05 


3.03 


0.66 


23 


6.111 


-6.115 


2.97 


2.87 


3.42 


24 


6. 116 


-6.120 


3.27 






25 


6.121 


-6.125 


2.58 






26 


6.126 


-6.130 


2.98 






27 


6.131 


-6.135 


3.19 






28 


6.136 


-6.140 


3.76 






29 


6.141 


-6.145 


4.04 






30 


6.146 


-6.150 


5.06 







A-42 



Project :Kesterson Selenium Study 

Date :July 1, 1988 

Sample Set :December 1987 Samples, Composites 

Received :November 30, 1987 



Site 

Pond 



ID 


Lab Number 


Sample 


Dupl icate 


RPD 


4 






ppm 


ppm 


7. 


51 


6.151 


-6.155 


18.43 






52 


6.156 


-6.160 


48.37 






53 


6.161 


-6. 165 


40.56 






54 


6.166 


-6.170 


28.90 






55 


6.171 


-6. 175 


67.06 






56 


6.176 


-6.180 


65.97 






57 


6.181 


-6.185 


46.72 






58 


6. 186 


-6.190 


31.08 






59 


6.191 


-6.195 


31.74 






60 


6.196 


-6.200 


34.59 






61 


6.201 


-6.205 


40.98 






62 


6.206 


-6.210 


50.25 






63 


6.211 


-6.215 


59.15 






64 


6.216 


-6.220 


45.94 






65 


6.221 


-6.225 


46.37 






66 


6.226 


-6.230 


32.65 







«RPD = Relative Percent Difference: [ 2* ( A-B ) / ( A-t-B ) ] * lOOV. 



A-43 



Project 


:Kesterson Se 


lenium Stud 


y 




Date 


:July 1, 1988 








Sample Se 


t :January 1988 


Samples, C 


omposites 




Received 


iJanuary 20, 


1988 






Site ID 


Lab Number 


Sample 


Dupl icate 


RPD 








ppm 


ppm 


■/. 


Pond 11 












1 


12.001 


-12.005 


3.84 






2 


12.006 


-12.010 


4.98 






3 


12.011 


-12.015 


4.50 






4 


12.016 


-12.020 


4.60 






5 


12.021 


-12.025 


3.79 


3.59 


5.42 


6 


12.026 


-12.030 


3.71 






7 


12.031 


-12.035 


3.67 






8 


12.036 


-12.040 


5.28 






9 


12.041 


-12.045 


4.24 






10 


12.046 


-12.050 


3.41 






11 


12.051 


-12.055 


3.58 






12 


12.056 


-12.060 


3.45 






13 


12.061 


-12.065 


3.36 






14 


12.066 


-12.070 


2.92 






15 


12.071 


-12.075 


3.75 






16 


12.076 


-12.080 


3.64 






17 


12.081 


-12.085 


2.89 






18 


12.086 


-12.090 


2.49 






19 


12.091 


-12.095 


2.33 






20 


12.096 


-12.100 


3.60 






21 


12.101 


-12.105 


3.47 






22 


12.106 


-12.110 


2.84 






23 


12.111 


-12.115 


2.54 






24 


12.116 


-12.120 


2.52 






25 


12.121 


-12.125 


2.88 






26 


12.126 


-12.130 


2.51 






27 


12.131 


-12.135 


2.38 


2.39 


0.42 


28 


12.136 


-12.140 


3.97 


3.80 


4.38 


29 


12.141 


-12.145 


3.82 






30 


12.146 


-12.150 


4.49 







A-44 



Project iKesterson Selenium Study 

Date :July 1, 1988 

Sample Set :January 1988 Samples, Composites 

Received :January 20, 1988 



Site ID Lab Number 

Pond 4 

51 12.151 -12.151 

52 12.156 -12.156 58.63 58.32 0.53 

53 12.161 -12.161 

54 12.166 -12.166 

55 12.171 -12.171 

56 12.176 -12.176 

57 12.181 -12.181 

58 12.186 -12.186 

59 12.191 -12.191 

60 12.196 -12.196 

61 12.201 -12.201 

62 12.206 -12.206 

63 12.211 -12.211 

64 12.216 -12.216 

65 12.221 -12.221 

66 12.226 -12.226 43.52 



*RPD = Relative Percent Difference: [ 2* ( A-B ) / ( A+B ) ] * 1007. 



Sample 


Dupl icate 


RPE 


ppm 


ppm 


7. 


19.03 






58.63 


58.32 


0. 


40.74 






32.65 






73.90 






79.60 






52.91 






33.32 






29.26 






35.00 






47.08 






60.00 






66.70 






37.98 







A-45 



Proj 


ect 


:Kesterson Selenium Stu 


Date 




:July 1,1988 




Samp 


le Se 


t :March 1988 Samp 


les, Co 


Received 


:Marc 


:h 8, 1988 




Site 


ID 


Lab Number 


Sample 










ppm 


Pond 


11 










1 


15.001 


-15.005 


4.27 




2 


15.006 


-15.010 


6.46 




3 


15.011 


-15.015 


5.02 




4 


15.016 


-15.020 


4.77 




5 


15.021 


-15.025 


4.27 




6 


15.026 


-15.030 


4.15 




7 


15.031 


-15.035 


3.63 




8 


15.036 


-15.040 


5.64 




9 


15.041 


-15.045 


4.70 




10 


15.046 


-15.050 


4.08 




11 


15.051 


-15.055 


4.16 




12 


15.056 


-15.060 


3.88 




13 


15.061 


-15.065 


3.49 




14 


15.066 


-15.070 


3.65 




15 


15.071 


-15.075 


4.19 




16 


15.076 


-15.080 


3.79 




17 


15.081 


-15.085 


3.20 




18 


15.086 


-15.090 


2.96 




19 


15.091 


-15.095 


2.74 




20 


15.096 


-15.100 


3.96 




21 


15.101 


-15.105 


3.99 




22 


15.106 


-15.110 


3.27 




23 


15.111 


-15.115 


2.98 




24 


15.116 


-15.120 


2.61 




25 


15.121 


-15.125 


3.47 




26 


15.126 


-15.130 


3.13 




27 


15.131 


-15.135 


2.72 




28 


15.136 


-15.140 


3.37 




29 


15.141 


-15.145 


3.37 




30 


15.146 


-15.150 


4.16 



)licate RPD 
ppm 7. 



3.69 1,64 



2.72 0.00 



A-46 



Project :Kesterson Selenium Study 

Date :July 1,1988 

Sample Set :March 1988 Samples, Composites 

Received iMarch 8, 1988 



Site 


ID 


Lab Number 


Sample 


Dupl icate 










ppm 


ppm 


Pond 


4 












51 


15.151 


-15.151 


20.61 






52 


15.156 


-15.156 


52.58 






53 


15.161 


-15. 161 


40.11 






54 


15.166 


-15.166 


31.77 






55 


15.171 


-15.171 


65.89 






56 


15.176 


-15.176 


65.71 






57 


15.181 


-15.181 


53.88 






58 


15.186 


-15.186 


30.82 






59 


15.191 


-15.191 


26.97 






60 


15.196 


-15.196 


31.62 






61 


15.201 


-15.201 


42.37 


42.96 




62 


15.206 


-15.206 


55.55 






63 


15.211 


-15.211 


51.80 






64 


15.216 


-15.216 


40.67 


40.85 




65 


15.221 


-15.221 


50.12 


48.77 




66 


15.226 


-15.226 


34.21 


34.59 


*RPD 


= Re 


lative Percent Di 


f f erence: 


C2*(A-B)/(( 



RPD 
7. 



1.38 



0.44 
2.73 
1.10 



A-47 



Project 


iKesterson Selenium Stud 


y 




Date 


:July 1, 1988 








Sample Se 


t -.Apr] 


. 1 1988 Samp 


les, Com 


posi tes 




Received 


:Marc 


.h 31, 1988 








Site ID 


Lab Number 


Sample 


Dupl icate 


RPD 








ppm 


ppm 


■/. 


Pond 11 












1 


17,001 


-17.005 


3.84 


3.84 


0. 


2 


17.006 


-17.010 


5.17 






3 


17.011 


-17.015 


4.19 






4 


17.016 


-17.020 


4.43 






5 


17.021 


-17.025 


3.62 






6 


17.026 


-17.030 


3.72 






7 


17.031 


-17.035 


3.81 






8 


17.036 


-17.040 


4.50 






9 


17.041 


-17.045 


4.06 






10 


17.046 


-17.050 


3.26 






11 


17.051 


-17.055 


3.80 






12 


17.056 


-17.060 


3.71 






13 


17.061 


-17.065 


3.24 






14 


17.066 


-17.070 


3.15 






15 


17.071 


-17.075 


3.64 






16 


17.076 


-17.080 


3.81 






17 


17.081 


-17.085 


2.81 






18 


17.086 


-17.090 


2.84 






19 


17.091 


-17.095 


2.63 






20 


17.096 


-17.100 


2.56 






21 


17.101 


-17.105 


3.68 






22 


17.106 


-17.110 


3.36 


3.31 


1. 


23 


17.111 


-17.115 


3.30 






24 


17.116 


-17.120 


2.75 






25 


17.121 


-17.125 


3.89 






26 


17.126 


-17.130 


3.48 






27 


17.131 


-17.135 


3.54 






28 


17.136 


-17.140 


3.87 






29 


17.141 


-17.145 


3.89 


4.15 


6. 


30 


17.146 


-17.150 


4.76 







A-48 



Project 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 
:July 1, 1988 

:April 1988 Samples, Composite 
zMarch 31, 1988 



Site ID 



Lab Number 



Sample Duplicate 
ppm ppm 



Pond 4 








51 


17.151 


-17. 151 


19.07 


52 


17.156 


-17.156 


44.66 


53 


17.161 


-17.161 


37.48 


54 


17.166 


-17.166 


28.42 


55 


17.171 


-17.171 


65. 11 


56 


17.176 


-17.176 


62.07 


57 


17.181 


-17. 181 


53.12 


58 


17.186 


-17.186 


30.78 


59 


17.191 


-17.191 


31.01 


60 


17.196 


-17.196 


28.78 


61 


17.201 


-17.201 


42.59 


62 


17.206 


-17.206 


46.89 


63 


17.211 


-17.211 


51.77 


64 


17.216 


-17.216 


40.38 


65 


17.221 


-17.221 


43.73 


66 


17.226 


-17.226 


32.10 


*RPD = Re 


lative Percent Di 


f f erence: 



RPD 



41.95 



3.81 



[2#( A-B)/ ( A+B) ]*1007. 



A-49 



Project 


:Kest 


erson Sel 


enium Study 






Date 


: July 


1, 1988 








Sample Set :riay 


1988 Samples, Composi 


tes 




Received 


:May 


4, 1988 








Site ID 


Lab Number 


Sample D 


upl icate 


RPD 








ppm 


ppm 


•/. 


Pond 11 












1 


19.001 


-19.005 


4.81 


4.96 


3.07 


2 


19.006 


-19.010 


6.40 






3 


19.011 


-19.015 


5.31 






4 


19.016 


-19.020 


5.77 






5 


19.021 


-19.025 


4.58 






6 


19.026 


-19.030 


4.22 






7 


19.031 


-19.035 


4.10 






8 


19.036 


-19.040 


6.06 






9 


19.041 


-19.045 


4.52 






10 


19.046 


-19.050 


3.87 






11 


19.051 


-19.055 


4.54 






12 


19.056 


-19.060 


3.94 






13 


19.061 


-19.065 


3.48 






14 


19.066 


-19.070 


3.76 






15 


19.071 


-19.075 


4.03 






16 


19.076 


-19,080 


4.13 






17 


19.081 


-19.085 


3.23 






18 


19.086 


-19.090 


3.20 






19 


19.091 


-19.095 


2.80 






20 


19.096 


-19.100 


3.28 






21 


19.101 


-19.105 


3.90 






22 


19.106 


-19.110 


3.27 






23 


19.111 


-19.115 


2.78 






24 


19.116 


-19.120 


2.72 






25 


19.121 


-19.125 


3.24 






26 


19.126 


-19.130 


3.19 






27 


19.131 


-19.135 


2.61 


2.59 


0.77 


28 


19.136 


-19.140 


3.44 


3.51 


2.01 


29 


19.141 


-19.145 


3.63 


- 




30 


19.146 


-19.150 


3.94 







A-5( 



Proj ec t 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 
:July i, 1988 

:May 1988 Samples, Composites 
:May 4, 1988 



Site ID 



Lab Number 



Sample Duplicate RPD 
ppm ppm ■/. 



Pond 4 








51 


19.151 


-19.151 


20.64 


52 


19.156 


-19.156 


37.24 


53 


19. 161 


-19.161 


34.19 


54 


19.166 


-19.166 


26.12 


55 


19.171 


-19.171 


54.15 


56 


19.176 


-19.176 


54.74 


57 


19. 181 


-19.181 


48.84 


58 


19.186 


-19.186 


29.16 


59 


19.191 


-19.191 


29.28 


60 


19.196 


-19.196 


30.36 


61 


19.201 


-19.201 


40.88 


62 


19.206 


-19.206 


47.79 


63 


19.211 


-19.211 


46.45 


64 


19.216 


-19.216 


45.09 


65 


19.221 


-19.221 


42.53 


66 


19.226 


-19.226 


31.13 


«RPD = Re 


lative Percent Di 


f f erence: 



[2«(A-B)/(A+B) jmiOO*/. 



A-51 



Project :Kesterson Selenium Study- 
Date :July 20, 1988 

Sample Set :June 1988 Samples, Composites 

Received :June 14, 1988 



Site ID Lab Number Sample Duplicate RPD 

ppm ppm ■/. 
Pond 11 

1 22.001 -22.005 3.84 4.10 6.55 

2 22.006 -22.010 4.78 

3 22.011 -22.015 4.30 

4 22.016 -22.020 5.17 5.38 3.98 

5 22.021 -22.025 4.60 
a 22.026 -22.030 4.28 

7 22.031 -22.035 4.25 

8 22.036 -22.040 5.64 

9 22.041 -22.045 4.52 

10 22.046 -22.050 3.64 

11 22.051 -22.055 4.49 

12 22.056 -22.060 4.03 

13 22.061 -22.065 3.46 

14 22.066 -22.070 3.12 

15 22.071 -22.075 3.85 

16 22.076 -22.080 4.08 

17 22.081 -22.085 3.06 

18 22.086 -22.090 3.19 

19 22.091 -22.095 2.96 

20 22.096 -22.100 3.38 3.82 12.22 

21 22.101 -22.105 3.93 

22 22.106 -22.110 3.79 

23 22.111 -22.115 3.07 

24 22.116 -22.120 2.69 

25 22.121 -22.125 3.78 

26 22.126 -22.130 3.53 

27 22.131 -22.135 2.56 

28 22.136 -22.140 3.51 

29 22.141 -22.145 3.77 

30 22.146 -22.150 4.57 



A-5; 



Proj ec t 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 
:July 20, 1988 

:June 1988 Samples, Composites 
:June 14, 1988 



Site ID 



Lab Number 



Pond 



4 

51 

52 

53 

54 

55 

56 

57 

58 

59 

60 

61 

62 

63 

64 

65 

66 



22.151 
22.156 
22.161 
22.166 
22.171 
22.176 
22.181 
22. 186 
22.191 
22.196 
22.201 
22.206 
22.211 
22.216 
22.221 
22.226 



-22.151 
-22.156 
-22.161 
-22.166 
-22.171 
-22.176 
-22. 181 
-22.186 
-22.191 
-22. 196 
-22.201 
-22.206 
-22.211 
-22.216 
-22.221 
-22.226 



Sample Duplicate 
ppm ppm 

22.09 
38.81 
44.39 
25.41 
60.74 
58.84 
57.31 
38.92 
33.72 
36. 55 
41.62 
47.83 
53.61 
44.07 
42.84 
25.69 



RPD 
7. 



*RPD = Relative Percent Difference: [2* ( A-B ) / ( A+B ) ] * 1007. 



A-53 



Project 


:Kesterson Selenium Study 






Date 


:August 12, 1988 








Sample Se 


t :July 1988 Sampl( 


=s , Composi 


tes 




Received 


:July 12, 1988 








Site ID 


Lab Number 


Sample Du 


pi icate 


RPD 








ppm 


ppm 


7. 


Pond 11 












1 


24.001 


-24.005 


5.16 


4.77 


7. 


2 


24.006 


-24.010 


6.06 






3 


24.011 


-24.015 


6.00 






4 


24.016 


-24.020 


5.73 






5 


24.021 


-24.025 


4.79 






6 


24.026 


-24.030 


4.45 






7 


24.031 


-24.035 


4.89 






8 


24.036 


-24.040 


5.84 






9 


24.041 


-24.045 


5.37 






10 


24.046 


-24.050 


3.57 


3.61 


1. 


11 


24.051 


-24.055 


4.36 






12 


24.056 


-24.060 


3.92 






13 


24.061 


-24.065 


3.61 






14 


24.066 


-24.070 


3.54 






15 


24.071 


-24.075 


4.09 






16 


24.076 


-24.080 


4.01 






17 


24.081 


-24.085 


3.29 






18 


24.086 


-24.090 


2.99 






19 


24.091 


-24.095 


3.29 






20 


24.096 


-24.100 


3.63 






21 


24.101 


-24.105 


3.54 






22 


24.106 


-24.110 


3.44 






23 


24.111 


-24.115 


2.93 






24 


24.116 


-24.120 


2.65 






25 


24.121 


-24.125 


3.39 






26 


24.126 


-24.130 


3.54 






27 


24.131 


-24.135 


2.95 






28 


24.136 


-24.140 


3.58 






29 


24.141 


-24.145 


3.51 






30 


24.146 


-24.150 


4.21 







A-54 



Project 


:Kesi 


terson Selenium Study 




Date 


:August 12, 19B8 






Sample Se 


t :July 1988 Sampl( 


=s , Composi 


tes 


Received 


:July 12, 1988 






Site ID 


Lab Number 


Sample Du 


pi icate 








ppm 


ppm 


Pond 4 










51 


24.151 


-24.155 


22.85 


21.41 


52 


24.156 


-24.160 


36.98 




53 


24.161 


-24.165 


47.46 




54 


24.166 


-24.170 


30.25 




55 


24.171 


-24.175 


63.74 




56 


24.176 


-24.180 


57.53 




57 


24.181 


-24.185 


47.04 


47.49 


58 


24.186 


-24.190 


28.35 




59 


24.191 


-24.195 


29.68 




60 


24.196 


-24.200 


31.81 




61 


24.201 


-24.205 


41.54 




62 


24.206 


-24.210 


44.73 




63 


24.211 


-24.215 


47.02 




64 


24.216 


-24.220 


40.78 




65 


24.221 


-24.225 


34.76 




66 


24.226 


-24.230 


19.55 





RPD 
•/. 

6.51 



0.95 



*RPD = Relative Percent Difference: [2* ( A-B ) / ( A+B ) ] * 1007. 



A- 55 



Project 
Date 

Sample Set 
Received 



:Kester5on Selenium Study 

:June 2, 1988 

rProfile Soil Samples, July 29, 1987 

:January 20, 1988 



Site ID 



Lab Number 



51 (1) 13.025 

51 (2) 13.026 

51 (3) 13.027 

51 (4) 13.028 

52 (1) 13.029 
52 (2) 13.030 
52 (3) 13.031 

52 (4) 13.032 

53 (1) 13.033 
53 (2) 13.034 
53 (3) 13.035 

53 (4) 13.036 

54 (1) 13.037 
54 (2) 13.038 
54 (3) 13.039 

54 (4) 13.040 

55 (1) 13.041 
55 (2) 13.042 
55 (3) 13.043 

55 (4) 13.044 

56 (1) 13.045 
56 (2) 13.046 
56 (3) 13.047 

56 (4) 13.048 

57 (1) 13.049 
57 (2) 13.050 
57 (3) 13.051 

57 (4) 13.052 

58 (1) 13.053 
58 (2) 13.054 
58 (3) 13.055 

58 (4) 13.056 

59 (1) 13.057 
59 (2) 13.058 
59 (3) 13.059 

59 (4) 13.060 

60 (1) 13.061 
60 (2) 13.062 
60 (3) 13.063 
60 (4) 13.064 



Sample 


Dupl icate 


Average 


ppm 


ppm 


ppm 


4.60 


4.73 


4.67 


ND 


ND 


— 


NO 


ND 


— 


ND 


ND 


— 


18.09 


17.75 


17.92 


3.30 


2.97 


3. 14 


ND 


ND 


— 


ND 


ND 


— 


15.92 


17.00 


16.46 


5.96 


5.96 


5.96 


3.24 


3.04 


3.14 


ND 


ND 


— 


8.56 


9.02 


8.79 


ND 


ND 


— 


ND 


ND 


— 


ND 


ND 


— 


18.05 


— 


— 


1.77 


— 


— 


ND 


ND 


— 


1.29 


1.24 


1.27 


23.59 


23.44 


23.52 


1.92 


1 .66 


1.79 


ND 


ND 


— 


ND 


ND 


— 


15.11 


14.90 


15.01 


ND 


ND 


— 


ND 


ND 


— 


1 .26 


1.23 


1.25 


55.58 


58.96 


57.27 


1.98 


1.57 


1.78 


1.04 


1.01 


1.03 


ND 


ND 


— 


21.64 


19.38 


20.51 


ND 


ND 


— 


ND 


ND 


— 


ND 


ND 


— 


10.06 


10.38 


10.22 


ND 


ND 


— 


ND 


ND 


— 


ND 


ND 


— 



RPD* 
7. 

2.79 



1 .90 
10. 53 



6. 56 
0.00 
6.37 

5.23 



3.95 

0.64 

14.53 



1.40 



2.41 

5.90 

23. 10 

2.93 

11.02 



3.13 



A-Si 



61 


(1) 




13.065 


18.09 


18.02 


18.06 


0.39 


61 


(2) 




13.066 


1.09 


ND 


— 


— 


61 


(3) 




13.067 


1.44 


1,62 


1.53 


11 ,76 


61 


(4) 




13.068 


ND 


ND 


— 


— 


62 


(1) 




13.069 


16.77 


16.80 


16.79 


0.18 


62 


(2) 




13.070 


ND 


ND 


— 


— 


62 


(3) 




13.071 


1.49 


1 .36 


1,43 


9.12 


62 


(4) 




13.072 


ND 


ND 


— 


— 


63 


(1) 




13.073 


9.81 


10.51 


10. 16 


6.89 


63 


(2) 




13.074 


ND 


ND 


— 


— 


63 


(3) 




13.075 


ND 


ND 


— 


— 


63 


(4) 




13.076 


ND 


ND 


— 


— 


64 


(1) 




13.077 


5.09 


4.14 


4.62 


20.59 


64 


(2) 




13.078 


2.78 


2.69 


2.74 


3,29 


64 


(3) 




13.079 


ND 


ND 


— 


— 


64 


(4) 




13.080 


ND 


ND 


~~"~ 


""■ — 




*RPD = 


= Re, 


lative Percent Diff 


erence: C2*(A- 


-B) / ( A+B) J* 100'/. 




**(1) 


= 


.0-0.5' 












(2) 


= 


.5-1.0' 












(3) 


= 1 


.0-1.5' 












(4) 


= 1 


.5-2.0' 











A-57 



Project 




:Kesterson Se 


Lenium Study 






Date 




rJune 2, 1988 










Sample Set 


rProfile Soil 


Samples , 


November 25, 


1987 




Received 


: December 18, 


1987 








Site ID 




Lab Number 


Sample 


Dupl icate 


Average 


RPD# 








ppm 


ppm 


ppm 


•/. 


2 ( 1 ) * * 


10.057 


5.50 


5.68 


5.59 


3.22 


2 ( 


2) 


10.058 


1.35 


1.20 


1.28 


11.76 


2 ( 


3) 


10.059 


ND 


ND 


-- 


— 


2 ( 


4) 


10.060 


ND 


ND 


— 


— 


4 ( 


1) 


10.061 


3.09 


3.32 


3.21 


7.18 


4 ( 


2) 


10.062 


1.13 


1.06 


1.10 


6.39 


4 ( 


3) 


10.063 


ND 


ND 


— 


— 


4 ( 


4) 


10.064 


ND 


ND 


— 


— 


6 ( 


1) 


10.065 


3.80 


4.08 


3.94 


7.11 


6 ( 


2) 


10.066 


ND 


ND 


— 


— 


6 1 


3) 


10.067 


ND 


ND 


— 


— 


6 ( 


4) 


10.068 


ND 


ND 


— 


— 


iO 


1 ) 


10.069 


3.13 


3.35 


3.24 


6.79 


10 ( 


2) 


10.070 


ND 


ND 


— 


— 


10 


3) 


10.071 


ND 


ND 


— 




10 


4) 


10.072 


ND 


ND 


-- 


— 


24 


i ) 


10.073 


1.61 


1.58 


1.60 


1.88 


24 


2) 


10.074 


ND 


ND 


— 


: 


24 


3) 


10.075 


ND 


ND 


— 





24 


4) 


10.076 


ND 


ND 


— 





25 


1 ) 


10.077 


1.54 


1.58 


1.56 


2.56 


25 


2) 


10.078 


ND 


ND 


— 


— 


25 


3) 


10.079 


ND 


ND 


— 


— 


25 


4) 


10.080 


ND 


ND 


— 


— 


51 


1 ) 


10.001 


16.81 


17.33 


17.07 


3.05 


51 


2) 


10.002 


ND 


ND 


— 


— 


51 


3) 


10.003 


ND 


ND 


— 


— 


51 


[4) 


10.004 


ND 


ND 


— 


— 


52 


( 1 ) 


10.005 


16.42 


17.55 


16.99 


6.65 


52 


(2) 


10.006 


ND 


ND 


— 


— 


52 


(3) 


10.007 


4.24 


4.32 


4.28 


1.87 


52 


(4) 


10.008 


. ND 


ND 


— 


— 


53 


( 1 ) 


10.009 


36.96 


37.94 


37.45 


2.62 


53 


(2) 


10.010 


ND 


ND 


— 


— 


53 


(3) 


10.011 


ND 


ND 


— 


— 


53 


(4) 


10.012 


ND 


ND 


— 


— 


54 


( 1 ) 


10.013 


6.82 


7.11 


6.97 


4.16 


54 


(2) 


10.014 


ND 


ND 


— 


— 


54 


(3) 


10.015 


ND 


ND 


— 


— 


54 


(4) 


10.016 


ND 


ND 


— 


— 



55 


( 1 ) 


10.017 


32.91 


33.81 


33.36 


55 


(2) 


10.018 


1.75 


1.67 


1.71 


55 


(3) 


10.019 


ND 


ND 


— 


55 


(4) 


10.020 


ND 


ND 


— 


56 


( 1 ) 


10.021 


33.59 


35.03 


34.31 


56 


(2) 


10.022 


ND 


ND 


— 


56 


(3) 


10.023 


3.68 


3.65 


3.67 


56 


(4) 


10.024 


ND 


ND 


— 


57 


(1) 


10.025 


12.16 


. 12.95 


12. 56 


57 


(2) 


10.026 


ND 


ND 


% 


57 


(3) 


10.027 


2.81 


2.92 


2.87 


57 


(4) 


10.028 


ND 


ND 


— 


58 


(1) 


10.029 


16.68 


17.27 


16.98 


58 


(2) 


10.030 


1.00 


ND 


— 


58 


(3) 


10.031 


1.09 


1.06 


1.08 


58 


(4) 


10.032 


1.05 


1 . 10 


1.08 


59 


( 1 ) 


10.033 


14.49 


15.78 


15.14 


59 


(2) 


10.034 


1.05 


1 .00 


1.03 


59 


(3) 


10.035 


1.47 


1.69 


1.58 


59 


(4) 


10.036 


ND 


ND 


— 


60 


( 1) 


10.037 


16.42 


16.70 


16.56 


60 


(2) 


10.038 


2.53 


2.51 


2.52 


60 


(3) 


10.039 


ND 


ND 


— 


60 


(4) 


10.040 


ND 


ND 


— 


61 


( 1 ) 


10.041 


15.77 


15.96 


15.87 


61 


(2) 


10.042 


ND 


ND 


— 


61 


(3) 


10.043 


1 .04 


1 .08 


1.06 


61 


(4) 


10.044 


ND 


ND 


— 


62 


(1) 


10.045 


30.79 


31.81 


31.30 


62 


(2) 


10.046 


1.59 


1.53 


1.56 


62 


(3) 


10.047 


ND 


1 .06 


— 


62 


(4) 


10.048 


ND 


ND 


— 


63 


(1) 


10.049 


51.34 


52.27 


51.81 


63 


(2) 


10.050 


2.45 


2.40 


2.43 


63 


(3) 


10.051 


1 . 18 


1.13 


1 . 16 


63 


(4) 


10.052 


ND 


ND 


— 


64 


(1) 


10.053 


9.76 


9.28 


9.52 


64 


(2) 


10.054 


ND 


ND 


— 


64 


(3) 


10.055 


2.67 


2.65 


2.66 


64 


(4) 


10.056 


ND 


ND 


— 



KtRPD = 


= Relative 


Percent 


*«(1) 


= 0.0-0.5' 




(2) 


= 0.5-1.0' 




(3) 


= 1.0-1.5' 




(4) 


= 1.5-2.0' 





Difference: [2* ( A-B ) / ( A+B ) ]*1007. 



A-59 



Project 
Date 

Sample Set 
Received 



:Kesterson Selenium Study 

:June 2, 1988 

:Profile Soil Samples, January 19, 1988 

:January 20, 1988 



Site ID 


Lab Number 


Sample 


Dupl icate 


Average 


RPD* 








ppm 


ppm 


ppm 


•/. 


59 


( 1 )** 


11.001 


33.68 


34.40 


34.04 


2.12 


59 


(2) 


11.002 


4,82 


5.55 


5.19 


14.08 


59 


(3) 


11.003 


NO 


ND 


— 


— 


59 


(4) 


11.004 


ND 


ND 


— 


— 


59 


(5) 


11.005 


ND 


ND 


— 


— 


59 


(6) 


11.006 


ND 


ND 


— 


— 


59 


(7) 


11 .007 


ND 


ND 


— 


— 


63 


(1) 


11 .008 


35.17 


24.02 


29.60 


37.68 


63 


(2) 


11.009 


13.44 


11.59 


12.52 


14.78 


63 


(3) 


11.010 


1.29 


1.16 


1.23 


10.61 


63 


(4) 


11.011 


3.46 


3.60 


3.53 


3.97 


63 


(5) 


11 .012 


ND 


ND 


— 


— 


63 


(6) 


11.013 


ND 


ND 


— 


— 


65/66 


(1) 


11.014 


37.54 


41.36 


39.45 


9.68 


65/66 


(2) 


11.015 


15.40 


15.63 


15.52 


1.48 


65/66 


(3) 


11.016 


2.13 


2.18 


2.16 


2.32 


65/66 


(4) 


11.017 


ND 


ND 






65/66 


(5) 


11.018 


ND 


ND 






65/66 


(6) 


11.019 


ND 


ND 






66 


(1) 


11.020 


31.05 


33.31 


32.18 


7.02 


66 


(2) 


11.021 


4.16 


4.26 


4.21 


2.38 


66 


(3) 


11.022 


3.51 


3.37 


3.44 


4.07 


66 


(4) 


11.023 


1.73 


1.74 


1.74 


0.58 


66 


(5) 


11.024 


ND 


1 .01 


— 


— 


66 


(6) 


11.025 


ND 


ND 


— 


— 



*RPD = 


= Relative 


Percen 


t 


**(1) 


= 


0-2" 






(2) 


= 


2-4" 






(3) 


= 


4-6" 






(4) 


= 


6-12" 






(5) 


= 


12-18" 






(6) 


= 


18-24" 






(7) 


= 


24-30" 







Difference: [2* ( A-B ) / ( A+B ) ]*100y. 



A-6( 



Project rKesterson Selenium Study 

Date :July 28, 1988 

Sample Set :Profile Soil Samples, July 24, 1988 

Received :July 20, 1988 



Site ID Lab # Sample 

ppm 



Pond 4 








63A* 




27.01 


31,7 


63B 




27.02 


2.08 


63C 




27.03 


2.34 


63D 




27.04 


ND 


* A = 0- 


6" 






B = 6- 


12" 






C = 12 


-IE 


i" 




D = 18 


-2A 


[•• 





A-61 



Project 


:Kesterson Selenium 


Study 




Date 


:September 15, 1988 






Sample Set :Profile 


Soil Samples, July 


24, V 


Received 


:July 25 


, 1988 






Site ID 


Lab # 


Sample Duplicate 


RPD 






ppm 


ppm 


7. 


51A 


28.001 


16.68 


15.74 


5. 


51B 


28.002 


2.10 






51C 


28.003 


3.56 






510 


28.004 


NO 






52A 


28.005 


5.60 






52B 


28.006 


NO 






52C 


28.007 


1.03 






52D 


28.008 


NO 






53A 


28.009 


12.08 






53B 


28.010 


1.22 






53C 


28.011 


9.54 






53D 


28.012 


1.37 






54A 


28.013 


15.80 


14.63 


7. 


54B 


28.014 


1.10 






54C 


28.015 


4.12 






54D 


28.016 


1.28 






55A 


28.017 


26.05 






55B 


28.018 


2.43 






55C 


28.019 


3.30 






550 


28.020 


NO 


. • 




56A 


28.021 


19.78 


' 




56B 


28.022 


2.25 






56C 


28.023 


13.62 






560 


28.024 


1.19 






57A 


28.025 


18.45 






57B 


28.026 


4.65 






57C 


28.027 


3.77 






570 


28.028 


1.63 






5BA 


28.029 


11.75 


13.82 


16. 


588 


28.030 


12.92 






5BC 


28.031 


5.06 






58D 


28.032 


3.89 






59A 


28.033 


15.87 






59B 


28.034 


3.73 






59C 


28.035 


3.20 






590 


28.036 


3.89 







1988 



80 



69 



A-6 



Project 


:Kesterson Selenium 


Study 


Date 


:September 15, 1988 




Sample Si 


pt :Profile 


Soi 1 Sampl ( 


3S , Jul 


Received 


:July 25, 


, 1988 




Site ID 


Lab # 


Sample Du| 


3l icate 






ppm 


ppm 


60A 


28.037 


10.09 




60B 


28.038 


1.41 




60C 


28.039. 


2.27 




60D 


28.040 


ND 


ND 


61A 


28.041 


14.77 


13.05 


61B 


28.042 


2.07 




61C 


28.043 


3.40 




61D 


28.044 


ND 




62A 


28.045 


12.58 




62B 


28.046 


3.13 




62C 


28.047 


NO 




62D 


28.048 


ND 




63A 


28.049 


15.00 




63B 


28.050 


2.58 




63C 


28.051 


4.33 




63D 


28.052 


1.08 




64A 


28.053 


6.59 




64B 


28.054 


1.47 




64C 


28.055 


ND 




64D 


28.056 


2.05 




65A 


28.057 


9.10 . 




65B 


28.058 


ND 




65C 


28.059 


3.86 




65D 


28.060 


2.75 




66A 


28.061 


8.01 


8.21 


66B 


28.062 


1.18 




66C 


28.063 


4.77 




66D 


28.064 


ND 




A = 0" - 


6" 






B = 6" - 


12" 






C = 12" - 


• 18" 






D = 18" - 


• 24" 







1988 



RPD 



12.37 



2.47 



APPENDIX B 

TOXICITY OF INHALED DIMETHYLSELENIDE 
IN ADULT RAT 



B-1 



B-2 
UNIVERSITY OF CALIFORNIA. DAVIS 



BtRKELt^ • DAMS • IKVINt. . LOS AN(.ELJ-S • Rl\ ERSlDt • SAN D1EC.O . SAN FR.^N(-ISCO U-vIET-:? ffiS^tiJi SAM A BARBAR,\ . sAMAl.Rl/ 




INSTITUTE FOR ENVIRONME^^■AL DAVIS, CALIFORNIA 95616 

HEALTH RESEARCH (916)752-1340 



22 September 1988 



Dr. W.T. Frankenberger, Jr. 
Department of Soil Science 
3401 Watkins Drive 
University of California 
Riverside, CA 92521 

Dear Dr. Frankenberger: 

Enclosed are six copies of the final report for our project "Toxicity of Inhaled 
Dimethyl selenide in Adult Rat." The main finding is that inhaled dimethyl selenide 
has remarkably low toxicity. We utilized extremely high concentrations in our 
exposures of rats without eliciting any remarkable detrimental responses. There 
were small statistically significant changes in some biochemical measurements in 
lung at 1 day post exposure, but these were all resolved by 7 days post exposure. 
At the highest level (8034 ppm) there was a detectable but minor injury to spleen 
in exposed rats indicated by a small but significant increase in protein and RNA 
in this organ. This agrees with other published studies that show 
dimethyl selenide to be a low-toxicity form of selenium in biological metabolic 
pathways. At high concentrations, dimethylselenide has a repulsive stench that 
makes it very unpleasant, however. 

Originally we proposed a colorimetric method for measuring selenium in tissues, 
but your review comments from the Bureau of Reclamation questioned the accuracy 
and sensitivity of that method, and recommended that we use Atomic Absorption 
methods. In investigating the various methods we found that the inductive coupled 
plasma (ICP) atomic emission spectroscopy method has become the standard in 
nutritional science and in the U.C.D. Veterinary School Diagnostic Laboratory 
because it is very accurate and extremely sensitive. This is the reason we used 
that method. The accuracy and sensitivity is confirmed by the results we obtained 
in the unexposed rats since they were able to detect the normal low levels found 
in the tissues of living animals at the nutritional level. 

Yours truly, 




Otto G. Raabe, Ph.D. 
Professor and Acting Director 



OGR/pc 

cc: M. Al-Bayati 



B-3 



TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RAT 



Otto G. Raabe and Mohammed A. Al-Bayati 

Co-principal Investigators 

and 

Steven Teague 

Fiorella Gielow 

Dale Uyeminami 

Contributing Staff 

Institute for Environmental Health Research 

University of California, Davis, California 95615 

Telephones (916) 752-7754 (Raabe) and 752-7750 (Al-Bayati) 

FINAL REPORT 



Submitted to: 
Dr. W.T. Frankenberger, Jr. 
Department of Soil Science 
University of California 
3401 Watkins Drive 
Riverside, California 92521 

23 September 1988 



Raabe & Al-Bayati— 2 

ABSTRACT 

The acute toxicity of the inhaled dimethyl selenide vapor was studied using the 
Flsher-344 rat as a model. A total of 85 adult SPF rats were exposed to four air 
concentration levels of this vapor for one hour. These levels were 0, 1607, 4499, 
and 8034 ppm. After exposure, the control and the exposed rats were housed in 
separate rooms in standard cages. The rats were observed frequently during the 
study period and they appeared normal. During the first 24 h post-inhalation, the 
exposed rats continued to exhale the dimethylselenide vapor as indicated by the 
charac-teristic odor in the animal rooms. Although the animal room was well 
ventilated, a respirator was needed to avoid the stenchy odor while working in the 
room. The exposed and control rats were sacrificed in groups of 4-10 rats at 
1 and 7 days post-inhalation. Necropsies were performed on all animals; the major 
tissues were grossly examined and then weighed. The organs appeared normal 
except, at one day, there was a significant increase in lung weight at concentra- 
tion 1607 and 8034 ppm (p<0.006), increase in lung weight but not significant at 
4499 ppm (p=0.07), and a significant increase in liver weight at concentration 
4499 and 8034 (p<0.02). Histological sections (Paraffin, H&E stained, 5-6 urn) of 
lung, liver, kidney, spleen, thymus, lymph nodes, pancreas, and adrenal gland were 
examined microscopically and appeared normal. Protein, DNA, and RNA content of 
lung and, liver were measured at all dose levels to measure edema in the tissues 
and to quantify the observed minor inflammatory response. The significant bio- 
chemical changes in the lung and liver were observed at one day. The changes in 
the lung were an increase in the protein content (p<0.05) at 1607 and 8034 ppm and 
an increase in RNA (p<0.05) and decrease in DNA content (p<0.005) at 4499 ppm. 
The change in the liver was reduction in DNA (p<0.02) at 4499 ppm. The protein. 



Raabe & Al-Bayati— 3 

RNA, and DNA of spleen and kidney of the rats exposed to and 8034 ppm were also 
measured and the changes were an increase in the protein and RNA content of spleen 
(p<0.05) at 7 days post exposure. The changes in the lung, and liver appeared to 
be a minor response as indicated by the histopathology data; and at seven days, 
the organs recovered completely. Selenium content of the lung and serum was 
determined by ICP method. Selenium level in the serum of the exposed rats was 
normal while the level in the lung was slightly elevated only at one day 
post-exposure. At one day, total lung retention of selenium was <10-8% of the 
inhaled dose. The data indicated that inhaled dimethyl selenide vapor is 
relatively nontoxic in rat. 



B-5 



PROJECT OBJECTIVES 

This study was designed to evaluate the acute toxicity of the inhaled 
dimethylselenide vapor in rat. To accomplish this objective, 85 rats were exposed 
to four air concentration levels (0, 1607, 4499, and 8034 ppm) of the vapor 
(Table 1). The rats were sacrificed in groups of 4 to 10 at one and seven days 
post-exposure and animal response were evaluated by the following parameters: (1) 
clinical signs, (1) body weight measurements, (3) gross and microscopic 
pathological lesions in the major organs (lung, liver, kidney, spleen, thymus, 
lymph nodes, pancreas, and adrenal gland), and the DNA, RNA, and protein contents 
of lung, liver, spleen and kidney were measured to quantitate the degree of edema 
in these tissue. Selenium level in serum and lung was measured and correlated to 
the degree of injury in the organs. 



>\uuuc u ni— uajruLi""'^ 



TABLE 1. THE TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS 



Gas Type 



Experimental Design 

Number 
Concentration* of rats 
(ppm) /group 



Number of rats per 
Sacrifice time (days)** 
(1) (7) 



Dimethyl selenide 
(CH3)2Se 




1607 
4499 
8034 



26 


13 


13 


20 


10 


10 


19 


10 


9 


20 


10 


10 



Total 

* Exposure duration = one hour. 

** Sacrifice time days post-exposure. 



85 



43 



42 



EXPERIMENTAL DESIGN AND METHODS 



I. CHEMICALS 



Dimethyl selenide liquid was purchased from Strem Chemicals, Inc. (7 Mulliken 
Way, Newburyport, MA 01950). Other chemicals and reagents for this project were 
purchased from a reputable commercial supplier with purity greater than 99%. 



II. ANIMAL CARE 

The animal care and experimentation sections of this project were carried out 
in accordance with the principles of the American Association for Accreditation of 
Laboratory Animal Care (AAALAC) in fully accredited facilities and following the 
Guiding Principles in the Care and Use of Laboratory Animals of the Department of 
Health, Education, and Welfare and The Animal Welfare Act. All experimental 
protocols at the University of California, Davis, were reviewed and approved by 



Raabe & Al-Bayati— 5 



the campus Veterinarian and the Animal Research Use Committee to assure 
conformance with the standards and humane treatment of the animals at all times. 
The regulations are enforced by regular inspections by AAALAC, the U.S. Department 
of Agriculture, and the Office of the Campus Veterinarian. 

A total of 85 male specific pathogen-free Fischer-344, young adult rats, age 
8-10 weeks and weighing 240 g (average) were used in these studies (Table 1). The 
animals were purchased from Bantin and Kingman, CA. The animals were shipped in 
superior filtered containers. Upon arrival, animals were housed in standard size 
cages in our animal housing facilities at LEHR and were fed water and rat chow ad 
lib throughout the study. Prior to exposure date, the rats were ear-tagged with 
an identification number and all animals were weighed on exposure and sacrificed 
dates. 

III. DIMETHYLSELENIDE EXPOSURE APPARATUS 

Exposure Apparatus 

The exposure apparatus (Figure 1) consisted of a syringe-pump device for 
delivery of liquid dimethylselenide at a steady rate having a vaporization section 
connected to a nose-only small rodent exposure chamber. The entire apparatus was 
placed in a glove box having a negative pressure with respect to the room and the 
exposure chamber was negative with respect to the glove box. Charcoal filters 
(Motor Guard) were used to capture the vapor passing through the chamber. The 
animals were exposed using the nose-only method described by Raabe et al . (1973). 
Respirators with charcoal canisters or supplied air breathing hoods were used by 
personnel while loading and removing animals after exposure. 



Raabe & Al-Bayati--6 



DIMETHYLSELENIDE EXPOSURE APPARATUS 



Vaporization 
section 




10 LPM 



DILUTION AIR 
EVAPORATION AIR 

20 LPM 



^g-^ 29 LPM 
TOTAL AIR OUT 






Bubblers 



Rotameter 



plexiglass body 



Rat 



RAT 

EXPOSURE 
TUBE 




Chamber 
pressure 

"o" ring stopper 



brass nose pc 



plunger adjustment 



figure 1 



Raabe & Al-Bayati— 7 

The syringe pump delivery device was made with a variable motor geared down to 
a slow enough speed to provide the desired amount of material in a syringe over 
the period of a one hour exposure. It was able to accomodate syringes of 
different sizes for the different chamber concentrations needed for the series of 
exposures. The syringes were placed in plastic boxes constructed to contain the 
liquid dimethylselenide in the event of a spill. A block of aluminum which moved 
along a pair of rods and was driven by a screw thread turned by a gear motor was 
used to operate the plunger part of the syringe. A piece of double-sticky 
adhesive tape held the plunger onto the block. The material was delivered to the 
vaporization section of the exposure apparatus located above the nose-only 
exposure chamber via a small bore teflon line. 

The vaporization section of the apparatus consisted of a section of pipe made 
of stainless-steel in which four stainless-steel fritted disks were placed. The 
dimethylselenide was introduced into the section by a stainless steel needle 
placed so the end was located in the center of the tube. Air was introduced 
through the topby means of a quick disconnect (Imperial Eastman) hose connector at 
a high enough flow rate to provide for complete vaporization. Dilution air was 
added through a series of holes placed around the circumference of the 
vaporization section. Pressure was controlled in the chamber by balancing the 
vaporization and mixing air with the total flow consisting of the chamber exhaust 
and the bubbler sample flow. Total air flow through the chamber was maintained at 
30 liters per minute throughout the exposure period of one hour. During the 
inhalation exposures, the appropriate chemical safety precaution were taken 
following protocols approved by the U.C. Davis Office of Environmental Health and 
Safety. 



Raabe & Al-Bayati--8 

IV. ANIMAL EXPOSURE TO DIMETHYLSELENIDE VAPOR 

The method of delivery for the liquid Dimethyl selenide solution to the animals 
in the vapor phase was accomplished as follows (Figure 2). The liquid 
dimethylselenide was placed in a syringe corresponding to the desired air 
concentration (10, 28, and 50 ml for exposure 1, 2, and 3, respectively; Table 1) 
that was to be delivered to the animals for the entire exposure of one hour. This 
was monitored for proper rate of delivery by checking the liquid consumption rate. 
The entire amount was vaporized in the vaporization section of the exposure 
apparatus before being passed into the nose-only exposure chamber. Air was pulled 
from the bottom of the chamber insuring even distribution of the vapor and passed 
through two sets of carbon filters. The exposure chamber was flushed with clean 
air for 15 minutes after exposure before the animals were removed. 

V. CLINICAL OBSERVATIONS AND NECROPSY 

During the quarantine and the study period, the animals were housed in two per 
polycarbonate cage under a 12 hour light/dark cycle at approximately 25°C, given 
proper care, and fed water and Purina Rodent Chow ad 1 ibidum . Animals were 
observed daily four times a day and they appeared normal during the 7 days 
post-inhalation. During the first 24 h, the animal exhaled considerable 
dimethylselenide as was apparent from the odor in the room. 

A group of rats (4-10) from each treatment were selected randomly, euthanized 
with an overdose of sodium pentothal (70 mg/kg, i.p.), and sacrificed at 1 and 7 
days post-exposure. Blood samples were be obtained by cardiac puncture and were 
taken for selenium measurement in the serum. The animals were subjected to a full 
gross necropsy by a veterinary pathologist and the target organs (lung, thymus. 



Raabe & Al-Bayati--9 



B-1 



VAPORIZATION SECTION 



filtered air 10 LPM 




Filtered 
air*.c^^ 

7 



^>'i^>'W>'x>M 






^^^^^^^^^( 






\ 



Teflon tubiing 



Fritted discs 



Nose only 
exposure chamber 
adaptor 



plastic containment box 



drive screw 



drive 
block 



Motor drive 




figure 2 



Raabe & Al -Bayati--10 



spleen, mesenteric lymph pancreas, kidneys, and liver) were separated, weighed, 
and taken for protocol assigned assays such as histopathological examination, 
biochemical measurements of DNA, RNA, protein, and selenium analysis as described 
below in the procedure section. 

VI. HISTOPATHOLOGICAL EXAMINATION OF TISSUE 

The liver, kidney, and spleen were weighed immediately upon removal and placed 
in a fixative (10% buffered formalin). In addition, mesenteric lymph nodes, 
thymus, pancreas, and adrenal gland were also taken and placed in the fixative. 
The lung from half of the animals were separated, cannulated, and were perfused 
with fixative under 30 cm of water pressure. The fixed tissue samples were 
processed, embedded in paraffin sectioned at 4 to 6 um, and representative 
sections were stained with Harris hematoxylin and eosin. 

VII. BIOCHEMICAL METHODS 

DNA, RNA, and protein were determined in the lung, liver, spleen, and kidney 
of the treated and control animals to measure the degree of edema in thes organs. 
RNA and DNA were measured by Wannemacher et al . (1965) method, assayed by and the 
protein was determined by Lowry method (Lowry et al . , 1951). Briefly the organs 
were weighed and frozen immediately upon removal. The tissues were homogenized 
individually and the homogenate aliquot taken and treated with 10% trichloroacetic 
acid (TCA). To remove the residual TCA and lipids from the precipitate, the 
pellet will be serially extracted with different solvent systems. These systems 
include 5 ml 95% ethanol saturated with sodium acetate, and 5 ml ethanol rethyl 
ether mixture (3:1). The excess ether is blown off with nitrogen and the pellet 
suspended in 5 ml 0.3 N KOH and heated at 50°C overnight in water bath capped with 



Raabe & Al-Bayati— 11 

marble. An aliquot of resulting KOH hydrolysate is used to measure the protein 
content and the remaining amount to measure the RNA and DNA content. Bovine serum 
albumin, yeast RNA type XI, and calf thymus DNA (Sigma) are used to prepare the 
standard curves for protein, RNA, and DNA, respectively. 

VIII. SELENIUM ANALYSIS PROCEDURE 

Selenium content of the lung and serum of control and exposed rats were 
determined by the inductive coupled plasma (ICP) method after digestion with 
perchloric and nitric acid at 210°C. The limit of detection of ICP for selenium 
is one ppb. The samples were processed by veterinary diagnostic laboratory at the 
University of California, Davis. 

RESULTS 

The experimental design is shown in Table 1 and the exposure apparatus design 
is shown in Figures 1 and 2. Body weight and organs weight measurements are 
presented in Table 2. Grossly, the organs appeared normal except that at one day 
post-inhalation, there were a increase in lung weight at 1607 and 8037 ppm 
(p<0.006) and in liver weight at 4499 and 8037 ppm (p<0.02). The lung weight at 
4499 ppm was also increased but not significant (p=0.07). The results of the 
microscopical examination of the tissues is presented in Table 3. The 
histological structure of lung, liver, kidney, spleen, thymus, lymph nodes, 
adrenal gland, and pancreas appeared normal. The biochemical changes in lung, 
liver, spleen, and kidney are presented in Table 4, 5, 6, and 7 respectively. 
The significant biochemical changes in the lung and liver were observed at one 
day; the significant changes (p<0.05) in the lung were an increase in the protein 
content at 1607 and 8034 ppm and an increase in RNA) and decrease in DNA content 



B-13 



Raabe & Al-Bayati— 12 



TABLE 2. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 
BODY AND ORGAN WEIGHT (Mean ± SD) 





Sacri 


fice 


Rat 


Organ 


weight as 


% of body weight 




Da> 


s 


Weight 










Treatment 


Post- 
Exposure 


(g) 


Lung* 


Liver* 


Kidney 


Spleen 






Expos 


ure No. 1, 


Dimethyl sel 


enide concentration = 


1607 ppm 


Control 


1 




236±11 


0.38±0.0 


3.7±0.2 


0.37±0.01 


0.22±0.02 


(n) 






(4) 


(2) 


(4) 


(4) 


(4) 


Exposed 


1 




233±17 


0.50±0.03a 


3.9±0.1 


0.38±0.02 


0.22±0.01 


(n) 






(10) 


(5) 


(9) 


(9) 


(8) 


Control 


7 




265±18 


0.36±0.05 


3.8±0.3 


0.36±0.02 


0.22±0.02 


(n) 






(4) 


(2) 


(4) 


(4) 


(4) 


Exposed 


7 




252±14 


0.41±0.03 


3.6±0.2 


0.36±0.01 


0.23±0.01 


(n) 






(10) 


(5) 


(9) 


(10) 


(10) 






Exposure No. 2, 


Dimethyl sel 


enide concentration = 


4499 ppm 


Control 


1 




259±30 


0.39±0.05 


3.6±0.2 


0.38±0.02 


0.24±0.03 


(n) 






(4) 


(2) 


(4) 


(4) 


(4) 


Exposed 


1 




242±14 


0.52±0.05*-* 


• 4.0±0.2b 


0.37±0.02 


0.24±0.02 


(n) 






(10) 


(5) 


(9) 


(10) 


(9) 


Control 


7 




265±18 


0.43±0.04 


3.7±0.3 


0.35±0.02 


0.23±0.01 


(n) 






(4) 


(2) 


(4) 


(4) 


(4) 


Exposed 


7 




272±13 


0.41±0.03 


3.5±0.7 


0.37±0.02 


0.23±0.02 


(n) 


• 




(10) 


(5) 


(10) 


(10) 


(10) 






Expos 


ure No. 3, 


Dimethyl sel 


enide concentration = 


8034 ppm 


Control 


1 




235±15 


0.39±0.00 


3.7±0.2 


0.38±0.03 


0.23±0.01 


(n) 






(5) 


(2) 


(5) 


(5) 


(5) 


Exposed 


1 




232±15 


0.49±0.01c 


4.0±0.1d 


0.37±0.03 


0.23±0.02 


(n) 






(10) 


(5) 


(9) 


(8) 


(8) 


Control 


7 




251±4 


0.38±0.02 


3.8±0.1 


0.36±0.02 


0.24±0.00 


(n) 






(5) 


(2) 


(5) 


(5) 


(5) 


Exposed 


7 




258±14 


0.40±0.02 


3.7±0.2 


0.37±0.03 


0.24±0.02 


(n) 






(10) 


(5) 


(10) 


(8) 


(9) 



* Significant increase in organ weight and p values for a^ b, c, and d are 
equal to 0.002, 0.02, 0.006, and 0.03 respectively. 



** 



p = 0.07, not significant increase but it show a tendency. 



Raabe & Al-Bayati— 13 ^"^^ 



TABLE 3. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 

HISTOPATOLOGY REPORT* 



Sacrifice 
Tissue Days 
Type Post- 

Exposure 


Number of sample 
Dimethyl 



exami 

seleni 

1607 


ned 
de 


microscopical ly pei 
Concentration ppm 
4499 8037 


- exposure 
Total 


Lung 1 


7 




5 




5 


5 * 


22 




7 




5 




5 


5 


22 


Kidney 1 


14 




5 




6 


5 


30 




13 




5 




6 


5 


30 


Liver 1 


12 




5 




6 


5 


28 




12 




5 




6 


5 


28 


Spleen 1 


11 




5 




6 


6 


27 




12 




5 




6 


5 


28 


Thymus 1 


10 




4 




6 


6 


26 




10 




4 




6 


5 


25 


Lymph 1 


10 




4 




5 


4 


23 


Node 7 


10 




4 




4 


5 


23 


Pancreas 1 


3 




1 







3 


7 




3 




3 




2 


3 


11 


Adrenal 1 


1 









1 


3 


5 




1 









1 


1 


3 



Total 



136 



60 



71 



71 



338 



* H&E stained paraffin section was examined microscopically from each 
organ and the tissues appeared normal. 



Raabe & Al-Bayati— 14 



TABLE 4. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 
BIOCHEMICAL CHANGES IN LUNG (Mean ± SE) 





Sacrifice 
Days 
Post- 
Exposure 


(n) 


LUNG 
Weight 

(g) 




mg per Lunc 


)* 


Treatment 


Protein 


RNA 


DNA 






Expos 


ure 


No. 1, Dimethyl 


selenide 


concentration 


= 1607 ppm 


Control 






2 


0.92±0.0 


99±4 


I2.7±1.4 


1.82±0.26 


Exposed 






5 


1.19±0.05a 


130±5b 


17.0±1.2 


2.07±0.15 


Control 






2 


0.94±0.01 


107±4 


14.9±0.3 


L78±0.04 


Exposed 






5 


1.00±0.05 


111±19 


17.1±1.1 


2.67±0.36 






Exposure 


No. 2, Dimethyl 


selenide 


concentration 


= 4499 ppm 


Control 






2 


1.11±0.05 


115±1 


15.2±0.3 


3.19±0.08 


Exposed 






5 


1.47±0.13^ 


132±9 


n.SiO.S*^ 


2.04±0.11^ 


Control 






2 


1.05±0.02 


114±0 


16.4±0.4 


2.94±0.84 


Exposed 






5 


1.15±0.03 


112±8 


18.3±1.9 


2.04±0.11 






Expos 


ure 


No. 3, Dimethyl 


selenide 


concentration 


= 8034 ppm 


Control 






2 


0.92±0.005 


94±1 


18.9±1.0 


2.60±0.15 


Exposed 






5 


1.15±0.03a 


lll±6b 


20.3±1.3 


2.46±0.16 


Control 






2 


0.95±0.03 


93±1 


16.9±1.5 


2.75±0.21 


Exposed 






5 


1.02±0.01 


93±3 


18.3±0.6 


2.42±0.32 



* Significant Change, p values for a, b are <0.005 and <0.05 respectively, 
c: not significant increase but it show a tendency (0.1<p<0.05). 



Raabe & Al-Bayati— 15 



B-17 



TABLE 5. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 
BIOCHEMICAL CHANGES IN LIVER (MEAN ± SE) 



Sacrifice LIVER 
Days Weight 
Treatment Post- (n) (g) 
Exposure 



Control 
Exposed 
Control 
Exposed 



mg per Liver 



Protein 



RNA 



DNA 



Exposure No. 1, Dimethyl selenide concentration = 1607 ppm 

1 4 8.88±0.27 1298±56 257±6 16.6±2.9 

1 5 9.09±0.28 1339±37 263±28 23.7±2.9 

7 4 9.93±0.46 1393±59 291±33 19.9±2.5 

7 5 8.81±0.29 1425±87 251±12 24.4±3.4 



Exposure No. 2, Dimethyl selenide concentration = 4499 ppm 

4 8.87±0.33 1419±72 226±13 23.2±1.2 

5 9.49±0.17 1495±79 200±9 18.211.1^ 

4 9.38±0.75 1525±108 231±19 25.2±1.5 

5 9.82±0.13 1620±69 205±7 24.7±2.1 



Control 


1 


Exposed 


1 


Control 


7 


Exposed 


7 



Control 


1 


Exposed 


1 


Control 


7 


Exposed 


7 



Exposure No. 3, Dimethyl selenide concentration = 8034 ppm 

5 9.05±0.31 1459±65 224±17 18.6±2.8 

5 9.03±0.32 1403±55 241±18 27.1±3.4 

4 9.32±0.14 1550±38 242±11 33.6±2.0 

5 9.46±0.33 1596±45 242±13 31.5±2.0 



a = significant change p<0.02. 



Raabe & Al-Bayati— 16 ^" 



TABLE 6. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 
BIOCHEMICAL CHANGES IN SPLEEN (MEAN ± SE) 





Sacrifice 
Days 
Post- 
Exposure 


(n) 


SPLEEN 
Weight 

(g) 




mg per Spleen 




Treatment* 


Protein 


RNA 


DNA 


Control 


1 


4 


0.52±Q.02 


63.9±6.2 


16.4±0.I 


I.74±0.17 


Exposed 


1 


5 


0.54±0.02 


65.4±2.2 


19.1±1.G 


1.66±0.05 


Control 


7 


4 


0.61±0.00 


73.2±6.4 


20.1±1.3 


1.91±0.11 


Exposed 


7 


5 


0.62±0.07 


98.0±8.0^ 


25.1±0.3^ 


1.89±0.17 



* = Exposure No. 3, Dimethyl selenide concentration = 8034 ppm 
a = Significant change, p<0.05. 



TABLE 7. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS; 
BIOCHEMICAL CHANGES IN KIDNEY (MEAN ± SE) 





Sacrifice 
Days 
Post- 
Exposure 


(n) 


KIDNEY 
Weight 

(g) 




mg per Ki 


dney 


Treatment* 


Protein 


RNA 


DNA 


Control 


1 


4 


0.85±0.03 


102±4 


12.5±0.2 


0.86±0.12 


Exposed 


1 


5 


0.86±0.02 


102±3 


15.7±0.8 


0.60±0.09 


Control 


7 


4 


0.87±0.03 


103±4 


15.1±0.5 


0.52±0.06 


Exposed 


7 


5 


0.87±0.01 


107±2 


15.9±1.2 


0.75±0.08a 



* = Exposure No. 3, Dimethyl selenide concentration = 8034 ppm 
a = Not significant, but it shows atendency (p=0.08). 



Raabe & AT -Bayati--17 



B-19 



(p<0.005) at 4499 ppm. the changes in the liver at one day was reduction in DNA 
(p<0.02) at 4499 ppm. The protein, RNA, and DNA of spleen and kidney of the rats 
exposed to 8034 ppm were also measured and the only significant changes (p<0.05) 
were an increase in the protein and RNA content of spleen at 7 days post exposure. 

The selenium content of the lung and serum were determined by ICP method and 
the result is presented in Table 8. Selenium level in the serum of the exposed 
rats was normal while the level in the lung was slightly elevated only at one day 
post-exposure. At one day, total lung retention of selenium was <10-8% of the 
inhaled dose. 

TABLE 8. TOXICITY OF THE INHALED DIMETHYLSELENIDE IN ADULT RATS: 
SELENIUM CONCENTRATION ppb IN TISSUE (MEAN ± SE) 



Treatment 



Control 
Exposed 
Exposed 



Sacrifice 

Days 

Post- (n) 
Exposure 



Selenium concentration ng/g 
SERUM LUNG* 



Exposure No. U Dimethylselenide concentration = 1607 ppm 
1+7 4 538±20 323+11 

1 5 569±74 382±10a 

7 5 540±10 336±10 



Exposure No. 2, Dimethylselenide concentration = 4499 ppm 
1+7 4 523±19 322±7 

1 5 545±44 399±93 

7 5 546±7 345±9 



Control 
Exposed 
Exposed 



Control 
Exposed 
Exposed 



Exposure No. 3, Dimethylselenide concentration 
1+7 4 552±49 358±4 

1 5 513±16 413±15b 

7 5 475±13 350±5 



8034 ppm 



Significant increase in selenium concentration and p values for 
a and b are <0.007 and <0.02 respectively, 
a Significant change, p<0.05. 



Raabe & Al-Bayati— 18 
DISCUSSION 

The data indicated that inhaled dimethyl selenide vapor is relatively nontoxic 
in rats. The increases in lung weight, lung protein content, and liver weight, 
were due to mild inflammatory responses in these organs which fully recovered a 
short time after exposure. Apparently there was some injury to the spleen at 8034 
ppm which was indicated by the increased spleen protein and RNA at 7 days. These 
observations indicated a normal recovery process after early injury. This is 
actually a normal response. Our results agree with other investigators in that 
dimethyl selenide is only l/500th as toxic as the selenite forni of Se (LD50 of 
dimethyl selenide = 1600 mg SE/kg in rat, I. P.; Wilber, 1980). Major metabol ites 
of Se are dimethyl selenide (exhaled) and trimethyl selenide (excreted in the 
urine). Palmer et al . (1970) stated that the methylated selenides and trimethyl- 
selenonium are the major metabolites present in the rat urine after administration 
of selenate, selenite, selenomethionine, selenocysteine, methyl selenocysteine, and 
seleniferous wheat. The biotransformation of selenite to dimethyl selenide has 
been characterize in great detail in vitro systems which included liver 
homogenates or liver fraction (Hsieh and Ganther, 1975). The result of selenium 
analysis in serum and lung suggested that the biological half live of dimethyl- 
selenide was very short and the compound was eliminated mainly via the lung. 

ACKNOWLEDGMENTS 

This research was supported by the University of California, Riverside, USDI 
Cooperative Agreement No. 7-FC-20-05240 with the University of California, Davis. 



B- 



Raabe & Al-Bayati— 19 ^'^^ 

LITERATURE CITED 

Lowry, 0., Rosebrough, N., and Randall, R. 1951. J. Biol. Chem. 193: 265 

Hsieh, H.S. and Ganther, H.E. 1975. Biochemistry 14: 1632-1636. 

Palmer, I.S., Grunsalus, R.P., Halverson, A.W., and Oslon, O.E. 1970. 
Biochim. Biophys. Acta 208: 260-266. 

Raabe, O.G., J.E. Bennick, M.E. Light, C.H. Hobbs , R.L. Thomas, and M.I. Tillery. 
1973. Toxicology and Applied Pharmacology 26:264-273. 

Willber, C.G. 1980. Clinical Toxicology 17(2): 171-230. 

Wannemacher, R. Jr., Banks, W. Jr., and Wunner, W. 1965. Anal. Biochem 11: 320. 



C-1 



APPENDIX C 



QUALITY ASSURANCE/QUALITY CONTROL PROCEDURES 



Section No. 1 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 



C-2 



MICROBIAL VOLATILIZATION OF SELENIUM FROM SOIL 



BUREAU OF RECLAMATION PROJECT OFFICER: 



UNIVERSITY OF CALIFORNIA, RIVERSIDE: W. T. FRANKENBERGER, JR. 



DURATION: OCTOBER 1, 1987 TO SEPTEMBER 30, 1989 



TYPE OF PROJECT: 



CONTRACTUAL AGREEMENTS WITH U.C. RIVERSIDE 
AND CALIFORNIA STATE UNIVERSITY FRESNO 
WITH UNIV. OF CALIFORNIA BEING RESPONSIBLE 
FOR AIR AND SOIL ANALYSES 



SUPPORTING ORGANIZATION: 



U.S. DEPARTMENT OF THE INTERIOR 
BUREAU OF RECLAMATION 
2800 COTTAGE WAY 
SACRAMENTO, CA 95825-1898 



APPROVALS: 

UCR PROJECT DIRECTOR: 

UCR PROJECT QA OFFICER: 

SWRCB PROJECT OFFICER: 



/J 




7 



( 



'y'A^KJ 



W. T. Frankenbergfi-rT Jr. 



Ulrich Karlson 



SWRCB QA OFFICER: 



C-3 



QUALITY ASSURANCE PROGRAM 
for 
MICROBIAL VOLATILIZATION OF SELENIUM FROM SOIL 



Project Sponsored by the 



U.S. DEPARTMENT OF THE INTERIOR 

BUREAU OF RECLAMATION 

Mid-Pacific Regional Office 



Prepared by 



W. T. Frankenberger, Jr. 



Department of Soil and Environmental Sciences 
University of California, Riverside 



C-4 
Section No. 2 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 



2.0 TABLE OF CONTENTS 

1.0 Title Page 

2.0 Table of Contents 

3.0 Project Description 

4.0 Project Organization 

5.0 Quality Assurance Objectives 

6.0 Sampling Procedures 

7.0 Sample Custody 

8.0 Calibration Procedures and Frequency 

9.0 Analytical Procedures 

10.0 Data Analysis, Validation, and Reporting 

11.0 Internal Quality Control Checks and Frequency 

12.0 Performance and System Audits 

13.0 Preventive Maintenance 

14.0 Routine Assessment of Data Precision, Accuracy and Completeness 

15.0 Corrective Action 

16.0 Quality Assurance Reports 



Section No. 3 C-5 
Revision No. 3 
Date: 01 May 88 
Page 1 of 2 



3.0 PROJECT DESCRIPTION 

3.1 Overview 

This study involves the initiation of field plot experiments 
to confirm the applicability of a fungal bioreclamation pro- 
cess in detoxifying seleniferous soils. In the laboratory it 
was shown that isolated soil fungi could take up selenium 
salts {Se03 and SeOt*) and convert them into methylated 
species, primarily dimethyl selenide (90%) and dimethyldiselenide 
(10%). Hydrogen selenide was not detected. We do not expect 
HzSe as a product of this transformation because of the oxidized 
conditions of our operation. Knowing that highly reduced condi- 
tions are necessary to generate H2S, one could surmise that H2Se 
would never be produced under the operational conditions we are 
proposing. Methylated gases are naturally volatilized into the 
atmosphere. Dimethylselenide has a relatively high LD^q (2200 mg 
kg--^ rat), thus a low toxicity threshold. Edaphic factors were 
shown to highly influence this transformation including a carbon 
source, moisture, aeration and activators. Among the carbon sour- 
ces, pectin was the most active for the methylation reaction. 
Because fruits are often high in pectin (35-45%), we selected 
orange peel for this experiment. Adequate aeration and moisture 
are needed because of the obligate aerobic nature of the fungi. A 
high moisture content can be detrimental to this process. 



Section No. 3 
Revision No. 3 
Date: 01 May 88 
Page 2 of 2 



Elements such as zinc, nickel or cobalt have been found to acti- 
vate this process up to 300%. Nitrogen addition (C:N = 20) also 
enhances the methylation reaction. Amendments that were tested in 
the field included: carbon sources (straw, cattle manure, orange 
peel, casein and gluten); aeration (rototilling 2 to 4X a month if 
weather permits); sprinkle irrigation (3-5 min/day; just enough to 
wet the surface; and ZnSO» applications. Selenium volatilization 
rates will be measured and the removal of residual selenium in the 
soil will be determined. The primary role of UCR is to provide 
direct technical oversight of the project, conduct analyses of 
selenium gas emission, and determine the selenium content in soil 
samples from the project site. 

3.2 Objectives 

3.2.1 The overall objective of the study is to provide a 
remedial measure which effectively removes residual 
selenium from soil . 

3.2.2 UCR is to provide competent analytical laboratory services 
for the determination of selenium gaseous emission and 
selenium content within soil samples. Total selenium will 
be determined by atomic absorption spectrometry (AAS) 
analyses. 



C-6 



Section No. 4 
Revision No. 3 
Date: 01 May 88 
Page 1 of 2 



C-7 



4.0 PROJECT ORGANIZATION AND RESPONSIBILITY 

A diagram describing UCR's organization is presented in the 
following figure. 



Project Director 
(or higher) 



Field Manager 



QA Officer 



Analytical Chemist 



Support Staff 



4.1 Project Director 

The Project Director, W. T. Frankenberger, is accountable for all 
operational activities including the examination of all data 
generated, quality assurance, and the preparation of all reports. 

4.2 Quality Assurance Officer 

The Quality Assurance Officer (Ulrich Karlson) is responsible for 
the periodic introduction of performance evaluation samples, where 
feasible, the evaluation of all sample logging/numbering proce- 
dures, the evaluation of all quality control data, and the pre- 
paration of quality assurance reports. These duties include system 
audits, validating data calculations, and examining procedures. 

4.3 The Field Manager collects soil samples to determine the depletion 
of selenium upon monthly intervals. This individual is also 



Section No. 4 C-8 
Revision No. 3 
Date: 01 May 88 
Page 2 of 2 



responsible for collecting gas samples, monitoring the methylated 
compounds evolved from each plot. Upon collection of the samples, 
the field manager will complete the chai n-of -custody forms and 
deliver soil samples to CSFU. Gas samples will be collected by 
the Field Manager and delivered to UCR for analyses. UCR will 
analyze approximately 10% of the soil samples as a check to CSFU. 

4.4 Support Staff 

The responsibilities of the support staff include sample container 
and glassware preparation, sample preservation, reagent and sample 
preparation, sample analyses, and reports. Staff members will be 
familiar with all laboratory procedures and quality assurance 
objectives. 



C-9 



Section No. 5 
Revision No. 3 
Date: 01 May 88 
Page 1 of 3 



5.0 QUALITY ASSURANCE OBJECTIVES FOR MEASUREMENT DATA 

5.1 Overview 

This Quality Assurance Project Plan will be carried out under the 
direction of the Project Quality Assurance Officer, Dr. Ulrich 
Karl son, who reports directly to the Project Director, Dr. W. T. 
Frankenberger. This document constitutes the Quality Assurance 
Project Plan. It covers the aspects of sample storage, transfer, 
transportation, analysis, and reporting. Separate quality objec- 
tives are addressed in other sections of this document and a 
listing of these objectives is presented in Table 5.1. 

TABLE 5.1 DATA QUALITY OBJECTIVES 



Data Quality QA Plan 

Objective How Determined Section Criteria 

Accuracy Reference material 11.1 +_20% of value if result 

is greater than 20 times 
CRDL; +4 times CRDL value 
if result is less than 
20 times CRDL 

Accuracy Recovery in spiked 

sample 11.3 80-120% of recovery 

Precision Duplicate analysis 11.2 15% if over 20 times CRDL; 

20% if 5 to 20 times CRDL; 
+1 CRDL if less than 
5 times CRDL 

Completeness Number of samples 14.3 20-100% of soil samples 
analyzed 95-100% of gas samples 



C-10 



Section No. 5 
Revision No. 3 
Date: 01 May 88 
Page 2 of 3 



Data Quality QA Plan 

Objective How Determined Section Criteria 

Representa- Analyze reference 11.1 See criteria for accuracy, 
tiveness materials 

Comparability Split samples also 11.2 See criteria for precision, 
analyzed by UCR 
laboratory 

Detection limit Lowest concentration 9.2.1 2 yg/L gas sample (DMSe, DMDSe] 
level that can be 1 mg/kg soil 

determined to be 
statistically dif- 
ferent from a blank 



5.2 Standard Operating Procedures 

5.2.1 The following sources of literature are used as guide- 
lines in developing the protocol for handling procedures, 
quality assurance, and analytical methods: Test Methods 
for Evaluating Solid Waste , SW-846, EPA, 1986; Handbook 
for Analytical Quality Control in Water and Wastewater 
Laboratories , EPA-600/4-79-019, 1979; Guidelines Establish - 
ing Test Procedures for the Analysis of Pollutants under 
the Clean Water Act ; Final Rule and Interim Final Rule 
and Proposed Rule , Federal Register, Part VIII, EPA 40 
CFR Part 136, Vol. 49, No. 209, 1984; Standard Methods 
for the Examination of Water and Wastewater , 16th Ed., 
APHA, AWWA, WPCF, 1980; and Methods of Soil Analysis, 
Part 2, Chemical and Microbiological Properties , 2nd. Ed., 



Section No. 5 C-ll 
Revision No. 3 
Date: 01 May 88 
Page 3 of 3 



American Society of Agronomy, 1982. Manual of Analytical 
Methods for the Analysis of Pesticides in Human and 
Environmental Samples , Health Effects Research Laboratory, 
EPA-600/8-80-038, 1980. Soil samples analyzed throughout 
this study will have the results reported in units of 
milligram (mg) of selenium per kilogram (kg) of dry soil 
weight. Volatile selenium emission rates will be expressed 
in yg m-^ h~^. Values of replicates, control and sample 
splits determined throughout the study will also be 
reported. 

5.2.2 Written standard operating procedures (SOP) for receipt of 
samples, tracking of custody and analysis, use of equip- 
ment and instrumentation, and assembly of completed data 
will be followed. These SOP will include use of standard 
data logging formats, log book entry procedures, and other 
written or printed documents relevant to the samples. 
Log books, printed forms or other written documentation 
will be available to describe the work performed in each 
of the following stages of analysis: 



sample transport • data reduction 

sample receipt • data reporting 

sample extraction-preparation • sample storage 
sample analysis 



C-12 
Section No. 6 

Revision No. 3 

Date: 01 May 88 

Page 1 of 6 

6.0 SAMPLING PROCEDURES 

6.1 Field Operations 

6.1.1 Volatile Selenium Emission Measurements 

A flux chamber will be employed which is slightly modified 

from the U.S. EPA environmental monitoring system (Las 

Vegas, Nevada): 

Schmidt, C. E., and W. D. Balfour. 1983. Direct gas emis- 
sion measurement techniques and the utilization of emissions 
data from hazardous waste sites. Procedings of the 1983 
ASCE National Specialty Conf. on Environ. Eng., Boulder, CO, 
July 6-8. p. 690. 

Dupont, R. R., and J. A. Reinemon. 1986. Evolution of 
volatilization of hazardous constituents of hazardous 
waste land treatment sites. EPA 660/2-86/071. 

This system will be used for sampling at least twice a month. 
The rationale for selecting this time interval for monitoring 
volatile Se was to follow changes upon weather conditions 
during the year. Evolution of Se gas fluctuates dramatically 
depending upon weather conditions. This system consists of a 
0.5 X 0.5 m square exterior channel galvanized steel inverted 
box. The vacuum will be subject to 2 L/min. This is an 
extremely low flux and should be representative of what one 
would expect upon minimum wind currents. Uniformity in the 
flow rate will be checked at each run with a flow meter. Cali- 
bration of the vacuum with a flow meter will be executed at the 
beginning and end of each run. As means for corrective action, 
samples will be re-taken if flow rates change significantly from 
normal. Alkali peroxide will be used to trap the gaseous selenium. 



C-13 



Section No. 6 
Revision No. 3 
Date: 01 May 88 
Page 2 of 6 



The chambers will be pressed about 2" into the soil with soil 
on the outside being bermed against the edges. Measurements 
will be conducted in the center of each plot. The duration of 
the measurements will be 1 hour with the starting and 
finishing times being recorded. Atmospheric and soil tem- 
perature will be monitored upon each gas sampling inside and 
outside the sampling enclosure and recorded in field logs. 

Selenium emission rates will be monitored at different times 
of the day to determine the diurnal cycling and flux during 
the seasons of the year. Methyl ation rates will be monitored 
upon a wide range of moisture and temperature regimes. 
When the temperature decreases, volatilization of selenium 
is expected to drop dramatically. Condensation during the 
evening hours may occur but the moisture will have little 
impact since the alkylselenides are insoluble in water and 
the trap consist of an alkali-HjOj solution. Once the 
Se gas is captured within the trap, the total Se content 
will be determined so that any change in .speciation will 
still be accounted for. Duplicate aliquots will be measured 
to obtain precision of internal quality controls. 



.Section No. 5 
Revision No. 3 
Date: 01 May 88 
Page 3 of 6 



The alkali-peroxide solution will be immediately analyzed 
at UCR for total Se. Aliquots will be analyzed by MS/ 
hydride generation. Blanks and spike traps will be included 
during the analyses to maintain QA/QC standards during these 
studies. The spike will be prepared by injecting dimethyl- 
selenide directly into the port within the flux chamber 
allowing the alkali peroxide to absorb the spike. Background 
Se volatilization rates are minimal (<1 ug/m2/d) without 
optimum management practices. 

6.1.2 Soil Samples 

Soil samples will be collected on a 4-week basis and exa- 
mined for their remaining Se content. A four-week interval 
was selected because of the long term period needed to observe 
a significant drop in Se content. The field test plots are 
defined in the treatment schedule of the workplan. The plots 
consists of 46 subplots, 30 in pond 11 and 16 in pond 4. Each 
of the subplots are 12' x 12' with boundary areas consisting 
of 8' widths. The untreated background control plots consist 
of designated areas adjacent to the treated subplots. These 
plots will indicate the background Se level in soils and 



C-14 



C-15 



Section No. 6 
Revision No. 3 
Date: 01 May 88 
Page 4 of 6 



air samples. Five subsamples within each subplot will be 
composite to account for spatial variability within the site. 
Each of the samples are spaced approximately 4.25' apart from 
each other as shown below. 




12' 



Comparison of results will be made at specified time intervals 
within each subplot. Pooled results are only expected to have 
significant meaning under a long-term basis. 
Soil samples will be collected with a soil probe 1" diameter 
down to a depth of 6" (the same depth as the rototiller mixes 
the soil). The Se content in soil profiles (down to a 2-ft 
depth) at 6" intervals will also be determined to assess the 
selenium distribution with soil depth. Each sample will be 
placed in zip-lock bags, labelled and packed on blue ice in 
an ice chest. Once all the soil samples are collected, 
the chest will be delivered to CSFU along with the chain-of- 
custody forms. The chain-of -custody record will be filed at 
UCR. All soil samples will be archived for further testing. 
The maximum period samples will be archived is up to one year 
following the submittal of the final report. Split-samples 



Section No. 6 
Revision No. 3 
Date: 01 May 88 
Page 5 of 6 



will be sent to UCR from CSFU after the latter organization 
homogenizes and processes the samples for extraction. The 
entire soil sample will be passed through a 2 mm sieve and 
ground to 100 mesh. After the sample is thoroughly mixed 
splits will be mailed for analyses. 

6.1.3 The collection and analyses of field quality control samples 
(i.e., replicates and/or backgrounds) at pre-established 
frequencies (2 weeks for gas samples and 4 weeks for soil 
samples) will be tested to evaluate sampling and analytical 
techniques for cross-contamination and variability. Equipment 
blanks will be prepared after the final rinse of the decontami- 
nation process, by pouring deionized water over the tools of 
collection into appropriate sample containers to assess cross- 
contamination. 

6.2 Shipping and Storing Samples 

6.2.1 Shipping : All samples will be refrigerated during shipment, 
and stored at 4°C or lower. Samples will be frozen, if 
feasible. Dry ice packs are acceptable as refrigerants. 
Samples will be shipped in insulated containers, all caps 
and lids will be checked for tightness prior to shipping. 

6.2.2 Storing : Recent laboratory studies (UCR) indicate that the 
holding time for Se captured in the gaseous form is not 



C-16 



C-17 
Section No. 6 

Revision No. 2 

Date: 06 Jan 88 

Page 6 of 6 



subject to loss in the alkali-peroxide solution for at least 
12 weeks. Soil samples will be kept in secured, refrigerated 
storage. For short term storage of. soil samples (not to 
exceed 4 weeks), the storage temperature will be kept at 4°C 
or lower. Fungal metabolism of soil Se would not be expected 
to occur at 4°C. For long-term storage of samples, the samples 
will be frozen. Storage will be in an environment where the 
sample number tags remain attached. Mechanical refrigeration 
units will be used. The use of ice as a refrigerant for 
samples is not allowed. 



Section No. 7 
Revision No. 3 
Date: 01 May 88 
Page 1 of 2 



7.0 SAMPLE CUSTODY 



7.1 Chain of Custody 

Chain-of-custody records will be put in practice upon collection 

of both gas and soil samples. A chain of custody record will 

allow us to trace the sample possession to the time of analysis. 

This record contains the following information: 

sample number 

signature of collector 

date and time of collection 

place and address of collection 

matrix 

signature of persons involved in the chain of possession 

inclusive dates of possession 

Our Quality Assurance Officer will inspect the sample, match it 

with the information on the label and with the chain-of-custody 

record , assign it a laboratory number, log the sample in the 

laboratory log book and store the sample until analyzed. Under 

the following conditions, samples will not be accepted in our 

laboratory for analysis: 

leaky plastic bags or bottles 

plastic container under high pressure (releasing gases) 

discrepancies between information on sample label & seal 

and information on chain-of-custody record & sample 

analysis request sheet 

Chain of custody procedures require that possession of samples be 
traceable from the time the samples are collected until comple- 
tion and submittal of analytical results. 



C-19 
Section No. 7 
Revision No. 3 
Date: 01 May 88 
Page 2 of 2 



A sample is considered under custody if: 



• it is in actual possession 

• it is in view after being in physical possession 

• it is placed in a secured area (accessible by or under 
the scrutiny of authorized personnel only) after being 
in possession 

7.2 Sample Handling, Storage and Holding Times 

7.2.1 All samples will be handled, prepared, transported and stored 
in a manner so as to minimize bulk loss, analyte loss, con- 
tamination or biological degradation. The sample containers 
will be clearly labeled with an indelible marker. Where 
appropriate, samples may be refrigerated or frozen to prevent 
biological degradation. 

7.2.2 Solid samples will be stored for the life of the contract 
unless the sample is consumed entirely for analysis. Soil and 
gas samples containing selenium remaining after completion 

of analysis will be stored at 4°C or colder for a minimum of 
90 days following submission of the data report to the Con- 
tracting Officer's representative. When that time interval 
has passed, the samples and containers will be disposed of 
properly. It is the sole responsibility of UCR personnel to 
ensure that all applicable regulations are followed in the 
disposal of samples or related chemicals. If the Contracting 
Officer should request return of a sample prior to the 
expiration interval, it will be returned in a manner that 
meets Department of Transportation regulations. 



C-20 



Section No. 8 
Revision No. 3 
Date: 01 May 88 
Page 1 of 2 



8.0 CALIBRATION PROCEDURES AND FREQUENCY 

8.1 Source of Standard Reagents 

The following vendors are used as the sources of reagents to 

conduct our analyses: 

Allied Fisher Scientific (Los Angeles, CA) 

Aldrich Chemical Co., Inc. (Milwaukee, WI) 

Sigma Chemical Co. (St. Louis, MO) 

Pierce Chemical Co. (Rockford, IL) 

Mallinckrodt Chemical Co. (St. Louis, MO) 

Burdick and Jackson (Muskegon, MI) 

EPA Standards (Quality Assurance Branch, Cincinnati, OH) 

All reagents are of ASC quality. All solvents are of pesticide 
grade. Other supplies have been purchased through Calgon Corp., 
Millipre, Kontes, Supelco, Alltech, Hewlett-Packard and Perkin-Elmer. 

8.2 Preparation of Quality Control Standards 

Calibration standards will be run on each analytical instrument 
at least at the beginning and end of each day. Standard stock 
solutions will be prepared from standard stock solutions and 
stored at 4°C. The secondary dilution standards are used to 
prepare appropriate concentrations of aqueous calibration stan- 
dards. Calibration standards will be prepared by using the same 
type of acids and preservatives as present in the samples. Cali- 
bration blanks will be analyzed at the beginning of each run, at 
a frequency of 5% during the run, and upon completion of the run. 
The instrument will be calibrated with a blank and at least three 
calibration standards. 



Section No. 8 C-21 

Revision No. 3 
Date: 01 May 88 
Page 2 of 2 



Examples of calibration problems are a change from a previously 
established value exceeding the Warning Limit {+2 standard 
deviations [SD]) or Control Limit (+3 SD). If a problem with 

• 

calibration arises, the Quality Assurance Officer will be 
immediately notified by the analyst. The Quality Assurance 
Officer will dictate appropriate diagnostic and corrective 
measures which will be carried out by the analyst and noted in 
the laboratory workbook. 

8.3 Corrective Measures for Calibration 

Calibration/reagent blanks will be analyzed at the beginning and 
end of each run. and at a frequency of at least one in 20 samples. 
If the calibration/reagent blank exceeds the CRDL, the analysis 
should be terminated, the problem corrected and the instrument 
recalibrated. 

If a discrepancy greater than 15% occurs between any of the matching 
calibration standards analyzed before and after the run, then the 
run should be void, the problem corrected and the run repeated. 



Section No. 9 
Revision No. 3 
Date: 01 May 
Page 1 of 8 



9.0 ANALYTICAL PROCEDURES 



9.1 Analytical Methods 

Both UCR and CSFU are using the same analytical method (AAS) for 

determination of selenium. The analytical methodology described 

in the following approved manual is used as a guideline for this 

study: 

• EPA methods for the Chemical Analysis of Water and Wastes, 
EPA-600/4-79-020 

The Appendix provides the soil digestion procedure (EPA Method 3050) 

and analytical method (EPA Method 270.3). Modifications of the 

above approved methods together with methodology developed by 

UCR personnel are also documented in the Appendix. Our digestion 

procedure involves a longer digestion period at a lower temperature 

(70-75°C for 10-15 h) compared to the EPA Method 3050 (95°C, 10 min), 

The limit of quantitation of any selenium method used must meet a 

Constituent Required Detection Limit (CRDL) of 0.1 mg/kg in soil. 

All data will be reported on a dry weight basis. Analytical 

controls will be maintained by strictly following written SOPs. 

If for some reason the SOP cannot be followed, deviations will be 

noted and reported in the data submittal package. Deviations 

from the approved analytical methodology manuals must meet 

requirements based on the method validation tests outlined 

subsequently in this section. 



Section No. 9 C-23 

Revision No. 3 
Date: 01 May 88 
Page 2 of 8 



9.2 Analytical Method Validation 

9.2.1 Limit of Detection 

Determine, for each method, the limit of detection (LOD), 
defined as the lowest concentration level that can be 
determined to be statistically different from a blank, and 
the limit of quantitation (LOQ), defined as the level 
above which quantitative results may be obtained with a 
specified degree of confidence. The LOD and LOO will be 
calculated by the lUPAC method, as given in Analytical 
Chemistry (1983) 5:712A-724A. 

9.2.2 Spike Recovery Test 

Perform a spike recovery test for each analyte on each 
matrix type analyzed. Each matrix will be spiked with 
an analyte at the limit of quantitation, at the mid-point 
and upper end of the calibration range. 

9.2.3 Standard Reference Material Test 

To the extent that a standard reference material (NBS, 
EPA, USGS, USBR) can be obtained, it will be run in con- 
junction with the spike recovery test. USBR has provided 
SRMs to both UCR and CSUF. 

9.2.4 Sample Duplicate Test 

Analyze in duplicate for the analyte in question, at least 
ten different samples, previously submitted for testing to 



Section No. 9 
Revision No. 3 
Date: 01 May 88 
Page 3 of 8 



other certified private or government laboratories and 
similar to the type expected. Duplicate samples will be 
analyzed on three nonconsecutive days with seven noncon- 
secutive measurements per day. Spike each sample at a 
level near the mid-point to upper end of the calibration 
range to check for possible interferences and note any 
analytical problems. 

9.2.5 Method Documentation 

Maintain a file containing all validation and modification 
reports. Upon completion of the validation tests, prepare 
a report detailing the results. 

9.2.6 Acceptance of the Method 

The Contracting Officer, the Contracting Officer's Tech- 
nical Representative, and a CAER representative will 
discuss the report and approve the method if it is 
appropriate. 

9.3 Control Charts 

Quality control charts will be constructed to be maintained by 
each analyst to demonstrate that the laboratory is in a state of 
control. 

9.4 Round-Robin Studies 

The UCR laboratory will participate in the Bureau of Reclamation- 
University of California, Davis, round-robin study and/or other 



Section No. 9 C-25 

Revision No. 3 
Date: 01 May 88 
Page 4 of 8 



standard reference sample programs specified by USBR. A copy of 
the report on the analytical results will be submitted to the 
Contracting Officer within 7 calendar days after receipt of the 
results from the sponsoring agency. 

9.5 Organization of Laboratory 

Personnel: Qualification of personnel is acknowledged to be very 
important to the laboratory. Personnel must have knowledge of 
laboratory protocol and suitable experience. Such experience can 
be obtained from laboratory experience in another facility or 
suitable college classwork. Anyone conducting analytical proce- 
dures in the laboratory is resonsible for the accuracy of those 
procedures and is answerable to the Quality Assurance Officer. 
New personnel will be trained and supervised by the Quality 
Assurance Officer. All personnel are expected to be familiar 
with and carefully follow the following Procedures Manual developed 
for use in the laboratory when conducting analyses of samples 
received. 

9.6 Laboratory Operating Practices 

9.6.1 Receiving Samples: Immediately upon receiving a sample, 

9.6.1.1 Record sample number in log book 

9.6.1.2 Record the information requested. 

9.6.1.3 If sample is not going to run immediately, follow 
appropriate sample storage procedures. 



Section No. 9 
Revision No. 3 
Date: 01 May 88 
Page 5 of 8 



9.6.2 Laboratory Procedure 

9.6.2.1 In lab book record date, time and procedure used. 

9.6.2.2 Check out instrument and/or materials to be used. 

9.6.2.3 Record all pertinent information regarding 
instrument and/or materials. 

9.6.2.4 Examine glassware routinely to confirm cleanliness. 

9.6.2.5 Check to make sure that the reagent and media used 
is the correct grade. 

9.6.2.6 If a new bottle of reagent or medium is put into 
use, check it off the inventory sheet. 

9.6.2.7 Follow designated procedure exactly. 

9.6.3 Record Keeping 

9.6.3.1 Record all weights, volumes, counts, and other data 
in log book. 

9.6.3.2 Briefly outline techniques used so that a back check 
can be performed if necessary. 

9.6.3.3 Record parameters of instrument and/or procedure 
in log book, 

9.6.3.4 Cite program used for instrumentation when applicable. 

9.6.3.5 If different technicians perform different tasks, 
initial log book indicating which tasks were per- 
formed by whom. 

9.6.4 Reports 

9.6.4.1 Record all results in log book. 

9.6.4.2 Retain all printouts in binder (be sure information 
includes sample number, date and time). 

9.6.4.3 Have all information clearly recorded so that a 
written report can be made. 



C-27 

Section No. 9 
Revision No. 3 
Date: 01 May 88 
Page 6 of 8 



9.6.5 Instruments 



9.6.5.1 Follow check procedure as shown on instruction 
sheet maintained near instrument. 

9.6.5.2 Bring instrument on line if necessary as per 
instructions on same sheet using parameters 
listed in procedure. 

9.6.5.3 Check program to determine that: 

• Linearity in the area in which work is intended 
has been established. 

• The syringe and needle used is the correct one 
and it is CLEAN. 

• The reagents being used are the proper ones and 
they have been checked by running a blank. 

• If information concerning the above is not 
avaiable, it will be developed by the analyst 
before proceeding further. 

• When beginning a procedure, list the page number 
of calibration run and blanks. 

• When results are obtained, record printout page 
number in log book. 

• If the instrument or other equipment does not 
appear to be working properly, contact the 
supervisor IMMEDIATELY. 

9.6.6 Quality Assurance Procedures 

9.6.6.1 Chemical Analyses - General 

• Run blanks of all new reagents used--record date, 
time and page number of printout in log book. 

• Run USBR standard reference materials (SRMs) 
with each set of samples. 

• Check linearity of instrument by running USGS 
reference materials with each set of samples. 



Section No. 9 
Revision No. 3 
Date: 01 May 88 
Page 7 of 8 



• Prepare fresh standards as needed. 

• Duplicate analysis of soil samples being analyzed 
for selenium will be performed. 

• When washing glassware, following procedure 
outlined in Method Manual. 

• Standard deviation calculations will be 
performed routinely at the end of each run. 

• All QA procedures will be listed in the log book. 

• Routine checks of accuracy will be performed. 



9.6.7 Glassware 



Glassware is cleaned with nonionic, metal-free detergent 
solution, soaked in acid solution (1+1 HNO3, 1 + 1 HCl , 
or aqua regia), and rinsed with metal free water. 



9.6.8 Laboratory Safety 

9.6.8.1 Lab coats will be worn at all times while working 
in the laboratory. 

9.6.8.2 Safety glasses will be worn while working with 
any solvents, condensers, or designated instru- 
mentation. 

9.6.8.3 Walkways will be clear of debris at all times. 

9.6.8.4 No horseplay of any kind will be tolerated. 

9.6.9 Laboratory Cleanliness 

9.6.9.1 Glassware will be washed, sterilized or 
solvent rinsed, depending upon its use, as soon 
as practical. 

9.6.9.2 Clean glassware will be returned to its proper 
place as soon as it has been solvent rinsed and 
properly capped. 



Section No. 9 C-29 
Revision No. 1 
Date: 01 May 88 
Page 8 of 8 



9.6.9.3 Counter tops will be kept clean. 

9.6.9.4 Any spills will be cleaned immediately and 
properly. 

9.6.9.5 Broken glassware will be placed in specified 
container and marked off inventory control sheet. 



9.6.10 Records 



Records on all relevant data are to be easily located in 
files that pertain to the specific analysis or question. 



C-30 



Section No. 10 
Revision No. 3 
Date: 01 May 88 
Page 1 of 3 



10.0 DATA ANALYSIS, VALIDATION, AND REPORTING 

10.1 Analysis 

The data analysis schemes to be applied to the raw data are 
indicated in the analytical procedure of each method. All data 
calculations will be performed by those individuals performing 
the analysis. 

10.2 Validation 

Individuals performing analysis and data calculation functions 
will be responsible for the examination of the finished data, as 
it is generated, to determine that it follows the existing trend 
set by the analysis of previous samples. A secondary check of 
the data by another analyst will confirm the validity and correct- 
ness of the data entry. If the data do not conform to the existing 
trend based on site selectivity, additional samples will be analyzed 
to determine the validity of the original sample results. Any 
decision to disregard the original results as being in error 
will be made by the QA Officer and the Project Director. All 
finished data will be inserted into laboratory notebooks and 
will be entered onto the appropriate record forms by those indi- 
viduals performing the analysis. 



C-31 



Section No. 10 
Revision No. 3 
Date: 01 May 88 
Page 2 of 3 



10.3 Record Keeping and Maintenance 



10.3.1 Instrument log books will be maintained with each instrument. 
All analytical parameters are to be recorded for each run and 
calibration data recorded daily. In addition, a record will 
be made of any conditions or incidents the analyst encounters 
which are in any way unusual, or deviate from the SOP. When 
maintenance is required, a record will be made of the symptom, 
the repair performed, and the individual performing the repair. 

10.3.2 All observations, tapes, printouts, and other raw material 
generated in the course of any analysis will be saved. They 
will be filed with reference to laboratory log number, date, 
batch number, analyst, and other information deemed pertinent. 
Also recorded in the laboratory notebook will be all weights 
or other types of raw data generated in the laboratory. All 
documentation in the laboratory notebook will be made in ink. 
Corrections to notebooks or other data records will be made 

by crossing a single inked line through the error, entering 
and initialing the correction, and recording the date. 

10.3.3 The records to be maintained in the laboratory include such 
items as sample tracking records, analysts' notebooks, bench 



Section No. 10 C-32 
Revision No. 3 
Date: 01 May 88 
Page 3 of 3 



sheets, instrument readout records, computer printouts, 
quality control data, and raw data. The records will be 
maintained for the life of the contract and they will be 
provided to the Contracting Officer upon request. Prior to 
completion of the contract, a request will be made to the 
Contracting Officer concerning disposal of the records. 
Any records requested by the Contracting Officer will be 
shipped at the Contractor's expense to the address provided. 



C-33 



Section No. 11 
Revision No. 3 
Date: 01 May 88 
Page 1 of 4 



11.0 INTERNAL QUALITY CONTROL CHECKS 



11.1 Standard Reference Samples 

Internal Quality Assurance samples (USBR Reference Materials) will 
be analyzed at a frequency of 10% with each set of soil analyses 
being performed. The method of preparation of the soil matrix 
will be the same as described in Section 9.1. These internal 
quality assurance analyses are conducted for the parameters 
being monitored by that analytical procedure. In addition, the 
compounds contained in the quality assurance sample will be 
representative of those compounds being monitored. Accuracy 
(relative percent error) is calculated as follows: 



Ace = [(D^ - D)/D] X 100 

a 



where Ace = accuracy (relative percent error) 

D, = analysis value of QA sample 
a 

D = accepted value of QA sample 



The results of all QA analyses and the percent deviation from 
the accepted analytical values will be recorded in the laboratory 
notebook. For accuracy (percent deviation from accepted value) use 
a control limit of +20% for sample values or more than 20 times the 
CRDL. For concentrations less than or equal to 20 times the 
CRDL, a percentage deviation of four times the CRDL divided by 



Section No. 11 
Revision No. 3 
Date: 01 May 88 
Page 2 of 4 



the accepted value times 100 will be used as the control limit. 
If deviations are found from the quality control checks, the 
analysis will be terminated and repeated. 

11.2 Duplicate Samples 

Duplicate samples will be analyzed for every 10 samples or every 
batch or every type of matrix, whichever is more frequent. The 
relative percent difference for each constituent is calculated 
as follows: 

RPD = [2 * Di - Dj)/Di + Dz] * 100% 
where RPD = relative percent difference 

Di = first sample value 

Dz = second sample value (duplicate) 
The results of all duplicate determinations and the calculated 
relative percent difference will be recorded in the laboratory 
notebook. For RPD, a control limit of 157. for sample values 
greater than 20 times the CRDL will be used. For concentrations 
greater than 5 times and less than 20 times the CRDL, a difference 
of 2 CRDLs or 207. will be permitted, whichever is greater. For 
concentrations less than 5 times the CDRL, a difference of one 
CRDL will be permitted. If either sample value is less than the 
CRDL, the RPD will not be calculated; in its place the notation 
of "NC" will be recorded in the laboratory notebook. If the 
precision falls outside the control limits, the analyses must 



C-34 



Section No. 11 
Revision No. 3 
Date: 01 May 88 
Page 3 of 4 



be terminated, the problems corrected, and the previous samples 
associated with that duplicate reanalyzed. If duplicate results 
are outside of the control limits, all pertinent data for samples 
associated with that duplicate sample will be flagged with an "*" 
in the laboratory notebook until the problem can be corrected and 
the samples reanalyzed. 

11.3 Spiked Sample Analyses (H O Sample s ) 

Spiked sample analyses will be conducted in those situations 
where standard reference samples are not available. Although 
some complex matrices are not easily simulated using spiked 
sample analysis techniques, where the sample matrix is com- 
patible with this method, at least one spiked sample analysis 
will be performed on samples of a similar matrix (i.e.. Ho). 
Matrix spikes will be prepared at levels defined in relation to 
the detection limit. The frequency will be at least one for each 
20 samples or per batch, whichever is more frequent. The spike 
will be added prior to any digestion and distillation steps as a 
check on the digestion and measurement methodology. An amount of 
analyte added to the sample will be approximately ten times the 
CRDL. Recovery values are calculated as follows: 



Rec = [(Dg -D)/S] X 100 



C-35 



Section No. 11 C-36 
Revision No. 3 
Date: 01 May 88 
Page 4 of 4 



where Rec = percent relative recovery 

Dg = value of sample with spike 

D = value of sample without spike 

S = amount of spike added 

Recovery values for sample spikes must fall within 80% to 120%. 
If the recovery falls outside of the range of 80-120%, the ana- 
lyses must be terminated, the problems corrected, and the pre- 
vious samples associated with the spike reanalyzed. When sample 
concentrations are less than the CRDL, the value of "0" will be 
used as the sample result concentration for purposes of calcu- 
lating spike recoveries. All spiked sample results will be 
recorded and reported in the laboratory log book. 

11.4 Blank Samples 

Calibration/reagent blanks will be analyzed at the beginning and 
end of each run at a frequency of at least one in every 20 samples, 
If the calibration/reagent blank exceeds the CRDL, the analysis 
will be terminated, the problem corrected, and the instrument 
recalibrated. 



C-37 



Section No. 12 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 

12.0 PERFORMANCE AND SYSTEM AUDITS 

12.1 Performance Audits 

Performance audits will be done periodically with samples being 
obtained from the Contracting Officer's QA Officer for each 
type of analysis being performed. 

12.2 System Audits 

System audits will be left to the discretion of the Project 
Officer. On-site evaluations will be conducted to help assure 
that all necessary quality control is being applied to the 
laboratory and, in addition, will serve as a mechanism for 
discussing weaknesses identified through QA performance sample 
analysis and data audits. An initial on-site visit will provide 
assurance that the UCR organization and personnel are qualified 
to complete the contract requirements, that adequate facilities 
and instrumentation are available, that proper analytical metho- 
dology is employed, and that adequate analytical quality control 
and data handling techniques are employed. Subsequent labora- 
tory reviews will allow the review team to determine if the 
Contractor has implemented the recommended and/or required 
corrective actions, with respect to quality assurance, made 
during previous on-site visits. 



Section No. 13 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 



13.0 PREVENTIVE MAINTENANCE 

13.1 Maintenance on field analytical instruments will be performed by 
in-house instrument maintenance personnel. Spare parts for the 
field apparatus include gas washing bottles (Fisher, 03-0408) 
and a Gast compressor/vaccuum pump (Fisher, 01093-70). Critical 
laboratory spare parts (AA lamps for selenium and hydride 
generator plastic tubing) will be maintained on hand. 

13.2 Fume hoods will be checked quarterly with evaluation of the 
ventilation capacity across the face of the fume hood. The 
inspection date will be posted on an exterior wall of the fume 
hoods. 

13.3 Equipment manuals containing trouble-shooting SOPs will be kept 
either with the instrument or with in-house maintenance 
personnel . 

13.4 Instrument operators are responsible for daily maintenance and 
for maintaining run logs. These logs will contain the date and 
description of routine maintenance procedures. Each entry into 
the run log will be signed by the individual making the entry. 
The run log will be reviewed periodically by the Quality 
Assurance Officer. 

13.5 In case of instrument malfunction, see corrective action 
(section 15). 



Section No. 14 ^"^^ 
Revision No. 3 
Date: 01 May 88 
Page 1 of 2 



14.0 ROUTINE ASSESSMENT OF DATA PRECISION, ACCURACY AND COMPLETENESS 

14.1 Precision will be assessed with each sample set for each 
analysis type. Precision will be expressed in terms of relative 
error as the percent deviation of the duplicate results from 
the original results obtained. The equation for determining 
precision is: 

RPD = [2(Dl - D2)/Di + 02] * 100 

where RPD = relative percent difference 
Di = first sample value 
D2 = second sample value (duplicate) 

14.2 Accuracy will be assessed on a regular basis in each set of 
samples for each analysis type by comparison of the analytical 
results of internal QA samples provided or approved by the QA 
Officer with accepted concentrations. Accuracy will be 
expressed in terms of relative error as the percent deviation 
of the analytical results from the known values. Accuracy is 
calculated as follows: 

ACC = [(D, - D)/D] X 100 

a 

where Ace = accuracy (relative percent error) 
D, = analysis value of QA sample 

a 

D = accepted value of QA sample 



Section No. 14 
Revision No. 3 
Date: 01 May 88 
Page 2 of 2 



In the absence of internal QA samples, accuracy will be assessed 
using spiked samples. Recovery of the spike will be used in 
this instance. Recovery is calculated as follows: 

Rec = [(D^ -D)/S] X 100 

where Rec = percent relative recovery 
D = value of sample with spike 

D = value of sample without spike 

S = amount of spike added 
As such round-robin analyses are conducted, they will be used 
to further assess accuracy. Assessment will be conducted peri- 
odically through a performance audit from samples provided 
by the QA Officer. 

14.3 Completeness will be assessed for each sample set and for each 
analysis type. The comparison for completeness will consist 
of a comparison of the number and type of analyses scheduled to 
be performed with those analyses successfully completed. Com- 
pleteness will be expressed as the percentage of analyses 
successfully completed relative to the number of analyses 
scheduled to be performed for each analysis type. Of all the 
gas samples collected, 95-100% will be analyzed. Of the soil 
samples collected, 20-100% will be analyzed. 



Section No. 15 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 



15.0 CORRECTIVE ACTION 

15.1 Should the accuracy of the standard reference sample analysis 
indicate a relative deviation greater than that indicated in 
Section 11.1, or should the precision of the duplicate analysis 
indicate a relative difference greater than that described in 
Section 11.2 or the recovery of a spiked sample not conform to 
the criteria specified in Section 11.3, or the level of reagent 
blank sample not conform to the criteria specified in Section 11.4, 
the reference, duplicate spiked or blank sample will be re- 
analyzed. Should the precision or accuracy remain outside of 

the above limits, the production samples in connection with the 
QC sampl.es will be re-analyzed. If the value obtained is still 
outside of the limit, the instrument will be recalibrated and 
the above process repeated. Instrument maintenance will be 
performed if deemed necessary by the analyst or the QA Officer. 
This process will be repeated until the relative difference is 
brought under that specified for precision and for recovery. 

15.2 Should completeness of the gas samples fall below 95% or the 
soil samples below 20% of that specified in Section 14.3 or 
should problems be encountered affecting comparability, the USBR 
QA Officer will be contacted to discuss the options available 
for rectifying the situation. 



C-41 



Section No. 16 C-42 
Revision No. 3 
Date: 01 May 88 
Page 1 of 1 



16.0 QUALITY ASSURANCE REPORTS 

16.1 Quality assurance reports will be submitted as required to the 
Project Officer and will include a detailed report of data 
precision, accuracy, and completeness for each type analysis. 
Included in the final report will be a summary of the practices 
used to assess data precision, accuracy, and completeness. 

16.2 All significant QA problems will be reported verbally to the 
Project Officer with a report to the QA Officer as soon as 
possible along with recommendations for corrective action. 

16.3 Any changes in QA procedures, analytical procedures, sampling 
locations and frequencies, etc. will be submitted in writing 
ta the Project Officer for approval. 



C-43 



APPENDIX 



REFERENCES: 

1. Handbook for Analytical Quality Control in Water and Waste- 
water Laboratories, EPA-600/4-79-019, March 1979. 

2. Methods for Chemical Analysis of Water and Wastes, EPA-600/4- 
79-020, March 1979. 

3. Microbiological Methods for Monitoring the Environment, 
EPA-600/8-78-017, December 1978. 

4. Standard Methods for the Examination of Water and Wastewater, 
16th edition, American Public Health Association, Washington, 
D.C., 1985. 

5. Test Methods for the Evaluation of Solid Waste, EPA SW-846, 
2nd edition, July 1982. 

6. ASTM Manual (American Society of Testing and Materials), 
Annual Publication. 

7. Manual for Association of Analytical Chemists. 

8. USGS, MEthods for Determination of Inorganic Substances in 
Water and Fluvial Sediments. 

9. USFWS, Patuxent Wildlife Research Center Analytical Manual 
(PWRCAM). 



C-45 



ADDITIONS/MODIFICATIONS TO METHOD 3050 

4.0 Apparatus and Materials 

25 mm o.d. glass digestion tubes (100 mL capacity) 

7.0 Procedure 

7.1 Initial processing of soil sample 

a. Thaw frozen soil sample and bring to room temperature. 

b. Open sample container and air dry soil samples at ambient 
laboratory temperature for 24 hours. (Note: high 
moisture, "wet", soil samples will require longer 
drying times. ) 

c. Pulverize dried sample and sieve through 10 mesh (2 mm 
diam. holes) sieve. Remove organic material and rock 
material that does not pass sieve. 

d. Mix sample well and remove approximately 25 g aliquot. 
Grind sample to pass 100 mesh sieve. Mix sample well. 

e. Weigh and transfer approximately 0.5 g of soil to 
digestion tube. 

7.2 Digest sample overnight (10-15 hours) at 70-75°C with 5 mL 
nitric acid and 5 mL distilled water. 

7.3 Add 30% hydrogen peroxide (3 mL total) in small increments 
(to prevent foaming); digest for an additional 4-8 hours. 

7.4 For hydride generation: Add 20 mL hydrochloric acid (4-6 M) 
and digest until frothing decreases. Then add additional 

10 mL hydrochloric acid and digest overnight (10-12 hours). 
Cool and dilute to 100 mL. Use appropriate additional 
dilution of aliquot of digest to get within calibration 
range on atomic absorption instrument (10-50 yg). 



C-46 



METHOD 3050 



ACID DIGESTION OF SLUDGES 



1.0 Scope and Application 

1.1 Method 3050 is an acid digestion procedure used to prepare 
sludge-type and soil samples for analysis by flame or furnace 
atomic absorption spectroscopy (AAS) or by inductively coupled 
argon plasma spectroscopy (ICP). Samples prepared by Method 
3050 may be analyzed by AAS or ICP for the following metals: 



antimony 


cadmium 


nickel 


arsemc 


chromium 


selenium 


barium 


copper 


silver 


beryllium 


lead 


thallium 
zinc 



1.2 Method 3050 may also be applicable to the analysis of other 
metals in slude-type samples. However, prior to using this 
method for other metals, it must be evaluated using the 
specific metal and matrix. 

2.0 Summary of Method 

2.1 A dried and pulverized sample is digested in nitric acid and 
hydrogen peroxide. The digestase is then refluxed with either 
nitric acid or hydrochloric acid. Hydrochloric acid is used 
as the final reflux acid for the furnace analysis of Sb or the 
flame analysis of Sb, Ba, Be, Cd, Cr, Cu, Pb, Ni , and Zn. 
Nitric acid is employed as the final reflux acid for the fur- 
nace analysis of As, Ba, Be, Cd, Cr, Cu, Pb, Ni , Se, Ag, Tl , 
and Zn or the flame analysis of Ag and Ti . 

3.0 Interferences 

3.1 Sludge samples can contain diverse matrix types, each of which 
may present its own analytical challenge. Spiked samples and 
any relevant standard reference material should be processed 
to aid in determining whether Method 3050 is applicable to a 
given waste. Nondestructive techniques such as neutron acti- 
vation analysis may also be helpful in evaluating the appli- 
cability of this digestion method. 

4.0 Apparatus and Materials 

4.1 125-ml conical Phillips' beakers 

4.2 watch glasses 

4.3 drying ovens that can be maintained at 30°C 

4.4 thermometer that covers range of 0-200°C 

4.5 Whatman No. 42 filter paper or equivalent 



C-47 



5.0 Reagents 



5.1 ASTM Type II water (ASTM D1193) : water should be monitored 
for impurities 

5.2 Concentrated nitric acid: Acid should be analyzed to deter- 
mine level of impurities. If impurities are detected, all 
analyses should be blank corrected. 

5.3 Concentrated hydrochloric acid: Acid should be analyzed to 
determine level of impurities. If impurities are detected, 
all analyses should be blank corrected. 

5.4 Hydrogen peroxide (30%): Oxidant should be analyzed to deter- 
mine level of impurities. If impurities are detected, all 
analyses should be blank corrected. 



6.0 Sample Collection, Preservation, and Handling 

6.1 All samples must have been collected using a sampling plan 
that addresses the considerations discussed in Section 1 of 
this manual . 

6.2 All sample containers must be prewashed with detergents, 
acids, and distilled deionized water. Plastic and glass con- 
tainers are both suitable. 

6.3 Nonaqueous samples will be refrigerated when possible, and 
analyzed as soon as possible. 



7.0 Procedure 

7.1 Weigh and transfer to a 125-ml conical Phillips' beaker a 1.0-g 
portion of sample which has been dried at 60°C, pulverized, 
and thoroughly mixed. 

7.2 Add 10 ml of 1:1 nitric acid (HNO3), mix the slurry, and cover 
with a watch glass. Heat the sample at 95°C and reflux for 10 
min. Allow the sample to cool, add 5 ml of concentrated HNO3, 
replace the watch glass, and reflux for 30 min. Do not allow 
the volume to be reduced to less than 5 ml while maintaining a 
covering of solution over the bottom of the beaker. 

7.3 After the second reflux step has been completed and the sample 
has cooled, add 2 ml of Type II water and 3 ml of 30% hydrogen 
peroxide (H2O2). Return the beaker to the hot plate for 
warming to start the peroxide reaction. Care must be taken to 
ensure that losses do not occur due to excessively vigorous 
effervescence. Heat until effervescence subsides, and cool 
the beaker. 



7.4 Continue to add 30% H2O2 in 1-ml aliquots with warming until 
the effervescence is minimal or until the general sample 
appearance is unchaged. (Note: Do not add more than a total 
of 10 ml 30% H2O2.) 

7.5 If the sample is being prepared for the furnace analysis of Ag 
and Sb or direct aspiration analysis of Ag, Sb, Ba, Be, Cd, 
Cr, Cu, Pb, Ni, Tl , and Zn, add 5 ml of 1:1 HCl and 10 ml of 
Type II water, return the covered beaker to the hot plate, and 
heat for an additional 10 min. After cooling, filter through 
Whatman No. 42 filter paper (or equivalent) and dilute to 100 
ml with Type li water (or centrifuge the sample). The diluted 
sample has an approximate acid concentration of 2.5% (v/v) HCl 
and 0.5% (v/v) HNO3 and is now ready for analysis. 

7.6 If the sample is being prepared for the furnace analysis of 
As, Ba, Be, Cd, Cr, Cu, Pb, Ni , Se, Tl , and Zn, continue 
heating the acid-peroxide digestate until the volume has been 
reduced to approximately 2 ml, add 10 ml of Type II water, 
and warm the mixture. After cooling, filter through Whatman 
No. 42 filter paper (or equivalent) and dilute to 100 ml with 
Type II water (or centrifuge the sample). The diluted 
digestate solution contains approximately 2% (v/v) HNO3. For 
analysis, withdraw aliquots of appropriate volume, and any 
required reagent or matrix modifier, and analyze by method of 
standard additions. 



8.0 Qual ity Control 

8.1 For each group of samples processed, procedural blanks (Type 
II water and reagents) should be carried throughout the entire 
sample-preparation and analytical process. These blanks will 
be useful in determining if samples are being contaminated. 

8.2 Duplicate samples should be processed on a routine basis. 
Duplicate samples will be used to determine precision. The 
sample load will dictate the frequency, but 10% is recommended. 

8.3 Spiked samples or standard reference materials should be 
employed to determine accuracy. A spiked sample should be 
included with each group of samples processed and whenever a 
new sample matrix is being analyzed. 

8.4 The concentration of all calibration standards should be 
verified against a quality control check sample obtained from 
an outside source. 

8.5 The method of standard addition will be used for the analysis 
of all extracts and whenever a new sample matrix is being 
analyzed. 



C-49 



SELENIUM 
Method 270.2 (Atomic Absorption, furnace technique) 



STORET NO. Total 01147 

Dissolved 01145 

Suspended 01146 



Optimum Concentration Range: 
Detection Limit: 2ug/l 



5-100 ug/1 



3. 



4. 



Preparation of Standard Solution 

1. Stock Sclenmm Solution: Dissolve 0.3453 g of seienous acid (actual assay 94 6% H,ScO ) 
mdeion^ed distilled water and maJce up to 200 ml. 1 ml = I mgSe(I000mg/l). 

^ !iT',S "°"' '''" ^*^'^* '" ''° « °^^^S ^^Sent grade Ni(N03),l6H,0 in 
deionized distilled water and make up to 100 ml. 

Nickel Nitrate Solution. 1%: Dilute 20 ml of the 5% nickel nitrate to 100 ml with 
deiomzed distilled water. 

Working Selenium Solution: Prepare dilutions of the stock solution to be used as 
cahbration staiidards at the time of analysis. Withdraw appropriate aliquots of the stock 
so ution. add 1 ml of cone. HNO, 2 ml of 30% H,0, and 2 ml of the 5% nickel nitrate 
solution. Dilute to 100 ml with deionized distilled water. 

Sample Preservation 

1. For sample handling and preservation, see part 4. 1 of the Atomic Absorption Methods 
section of this manual. 

Sample Preparation 

1. Transfer 100 ml of well-mixed sample to a 250 ml Griffin beaker, add 2 ml of 30% H,0, 
and sufficient cone. HNO3 to result in an acid concentration of l%(v/v). Heat for I hour 
at 95*C or until the volume is slightly less than 50 ml. 

2. Cool and bring back to 50 ml with deionized distilled water. 

3. Pipet 5 ml of this digested solution into a 10-ml voiumetnc nask, add 1 ml of the 1% 
nickel nitrate solution and dilute to 10 ml with deionized distilled water. The sample is 
now ready for injection into the furnace. NOTE: If solubilization or digestion is not 
required adjust the HNO3 concentration of the sample to 1% (v/v) and add 2 ml of 30% 
H^Oj and 2 ml of 5% nickel nitrate to each 100 ml of sample. The volume of the 
calibration standard should be adjusted with deionized distilled water to match the 
volume change of the sample. 



Approved for NPDES and SDWA 
Issued 1978 



270.2-1 



C-50 



Instrument Parameters 

1. Drying time and temperature: 30 sec (31 125°C 

2. Chamng time and temperature: 30 sec (.5» 1 200*C 

3. Atomizing time and temperature: 10 sec @ 2700*C 

4. Purge Gas Atmosphere: Argon 

5. Wavelength: 196.0 nm. 

6. Other operating parameters should be set as specified by the particular instrument 
manufacturer. 

Analysis Procedure 

1. For the analysis procedure and the calculation see "Furnace Procedure" part 9.3 of the 
Atomic Absorption Methods section of this manual. 

Notes 

1 . The above concentration values and instrument conditions are for a Perkin-Elmer HGA- 
2100. based on the use of a 20 ul injection, puri^tr j^us interrupt and non-pyrolytic 

graphite. Smaller size furnace devices or those employing faster rates of atomization can 
be operated using lower atomization temperatures for shorter time periods than the 
above recommended settings. 

2. The use of background correction is recommended. 

3. Selenium analysis suffers interference from chlorides ( > 800 mg/1) and sulfate ( > 200 
mg/1). For the analysis of industrial effluents and samples with concentrations of sulfate 
from 200 to 2000 mg/1, both samples and standards should be prepared to contam 1% 
nickel. 

4. For every sample matrix analyzed, verification is necessary to determine that method of 
standard addition is not required (see part 5.2.1 of the Atomic Absorption Methods 
section of this manual). 

5. For quality control requirements and optional recommendations for use in drinking 
water analyses, see part lOof the Atomic Absorption Methods section of this manual. 

6. If method of standard addition is required, follow the procedure given earlier m part 8.5 
of the Atomic Absorption Methods section of this manual. 

7. Data to entered into STORET must be reported as ug/ 1 . 

Precision and Accuracy 

1. Using a sewage treatment plant effluent containing <2 ug/l and spiked with a 
concentration of 20 ug/1, a recovery of 99% was obtained. 

2. Using a series of industrial waste effluents spiked at a 50 ug/1 level, recoveries ranged 
from 94 to 112%. 

3. Using a 0.1% nickel nitrate solution as a synthetic matrix with selenium concentrations 
of 5, 10. 20. 40, 50, and 100 ug/1. relative standard deviations of 14.2, 1 1.6, 9.3, 7.2, 6.4 
and 4. 1%, respectively, were obtained at the 95% confidence level. 



270.2-2 



C-51 



4. 



of Tw ' a^r V '^T'-' "'"^ ^'"^'"""'- °''° ^^P -^- ^P'^«^ - concentrations 
X 10 and .0 ^g Se/1. the standard deviations were rO.6. -0 4 and *0 5 
respectively. Recovenes at these levels were 92%. 98%. and 100%. respectively. ' ' ' 



Reference: 

"Det 
Abso 

Newsletter U, 109(1975) 



ence: 

I^'rr/ ^'""""" '" *""• *^='"="'''"- S«lin,.„, and Sludge By Flam.l«3 Atomic 



270.2-3 



C-52 



SELENIUM 

Method 270.3 (Atomic Absorption, gaseous hydride) 

STORET NO. Total 01147 

Dissolved 01145 

Suspended 01146 

1. Scope and Application 

1.1 The gaseous hydride method determines inorganic selenium when present in 
concentrations at or above 2 ug/1. The method is applicable to drinking water and most 
fresh and saline waters, in the absence of high concentrations of chromium, cobalt, 
copper, mercury, molybdenum, nickel and silver. 

2. Summary of Method 

2. 1 Selenium in the sample is reduced from the + 6 oxidation state to the +4 oxidation state 
by the addition of SnCl,. Zinc is added to the acidified sample, producing hydrogen and 
converting the selenium to the hydndc, SeHj. The gaseous selenium hydride is swept into 
an argon-hydrogen flame of an atomic absorption spectrophotometer. The working 
range of the method is 2-20 ug/1 using the 196.0 nm wavelength. 

3. Comments 

3. 1 In analyzing drinking water and most surface and ground waters, interferences are rarely 
encountered. Industrial waste samples should be spiked with a known amount of 
selenium to establish adequate recovery. 

3.2 Organic forms of selenium must be converted to an inorganic form and organic matter 
must be oxidized before beginning the analysis. The oxidation procedure given in method 
206.5 (Standard Methods, Hth Ed. 404B. p 285, Procedure 4. 1) should be used. 

3.3 For sample handling and preservation, see part 4.1 of the Atomic Absorption Methods 
section of this manual. 

3.4 For quality control requirements and optional recommendations for use in drinking 
water analyses, see part 10 of the Atomic Absorption Methods section of this manual. 

3.5 Data to be entered into STORET must be reported as ug/1. 

4. Precision and Accuracy 

4.1 Ten replicate solutions of selenium oxide at the 5, 10 and 15 ug/1 level were analyzed by 
a single laboratory. Standard deviations at these levels were ±0.6, rl.l and ±2.9 with 
recovenes of 100. 100 and 101%. (Caldwell. J. S., Lishka, R. J., and McFarren. E. F., 
"Evaluation of a Low-Cost Arsenic and Selenium Determination at Microgram per Liter 
Uvels", JAWWA, vol 65, p. 73 1. Nov. 1973.) 



Approved for NPDES and SDWA 
Issued 1974 



270.3-1 



C-53 



5. References 

5.1 Except for the pcrchlonc acid step, the procedure to be used for this determination is 
found in: 

Standard Methods for the Examination of Water and Wastewater. 14th Edition, p 159. 
Method 30 lA(VII). (1975) 



270.3-2 



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D-1 



APPENDIX D 
QUOTATIONS 



D-2 



SAN JOAQUIN 

21 850 W. MANNING AVE 

SAN JOAQUIN, CA 93660 

(209) 693-2441 



IRRIGATION ENGINEERS, INC. 

BAKERSFIELO (Main) OFFICE 

P.O. BOX 70188 

410 EAST PLANZ ROAD 

BAKERSFIELD, CALIFORNIA 93387 

TELEPHONE (805) 831-3535 



GREENFIELD 

PINE AND EL GAMINO REAL 

GREENFIELD, CA 93927 

(408) 674-5550 



OCTOBER 14,1988 

DR. W.T. ETRANKENBERGER Jr. 

UNIVERSITY OF CALIFORNIA RIVERSIDE 

DEFT. OF SOIL AND ENVIRONMENTAL 

SCIENCIES-84 

RIVERSIDE, CA. 92521-0424 



DEAR DR. FRANKENBERCT3^ : 

THIS IS AN ESTIMATION OF IRRIGATION EQUIPMENT REQUIRED AT KESTERSCN 
RESERVOIR. THE MAINLINE QUANTITIES COULD VARY DEPENDING ON WERE 
BOOSTER PUMP OR WATER SOURCE IS LOCATED. THE FOLLOWING QUOTE IS BASED 
ON ASOLID SET SYSTEM FOR 1200 ACRES. THE FOLLOWING PRICE STRUCTURE 
IS BASED ON A ANUAL RENTAL. 



235jt. 12"x45' ALUM. MAINLINE W/V 2.20ft. %9.00/jt $23,265.00 

235jt. 10"x45' ALUM. MAINLINE W/V 1.86ft. %3.70jt. $19,669.50 
235ea. 10" RINGLOCK N/C 

37,200jt. 3"x30' ALUM. SPRINKLER PIPE W/24"RISER W/ 10-20 SPRK. 
W/7/64 NOZ. .26ft. f 7.80jt. $290,160.00 

938ea. 3" END PLUGS 

4ea. 10" RINGLOCK END PLUGS 

235ea. 12" RINGLOCKS 

470ea, 4"X3"X3" VALVE OPENING TEES 

4ea. 12"X10" RINGLOCK REDUCERS 

2ea. 12" RINGLOCK CLAMPS 

2ea. 10" RINGLOCK CLAMPS 

4ea. 1800-2200 gpm PUMPS 

4ea. 12"X DISCHARGE (S. DROP) 

4ea. SUCTION HOSES W/F(XT VT^VES W/PUMP 

1 LOT FITTING FOR UNKNOWN HOOKUPS et. 



sincerly 



■^ 2.80ea. 


$ 


2,626.40 


?24.00ea. 


$ 


96.00 
N/C 


$21.00ea 


$ 


9,870.00 


$42.00ea 


$ 


168.00 
N/C 

N/C 


$13,200.00 


$52,800.00 


$66.00 


$ 


264.00 

N/C 




$ 


500.00 




$399,418.90 


6.5%tax$ 


25,962.23 




$425,381.13 




PRICES SUBJECT TO CHANGE & AVMLABILITY 



JIM GARNER 

MANAGER 
JG:]C 



D-3 



N0U-18-'8a FRI 16:20 ID:UflTER UflYS 



•AN JOAOUIN 

21BS0W. MANNINQ 
$AN JOAOUIN, CA i»MO 
PHONE (20a)6»9-2441 



IRRIQATION ENGINEERS, INC. 



TEL NO: 1-805-831-3588 
aMENPIELD 



8097 P01 



PINE » et OAMINO REAL 
OneeN FIELD. CAB39ZT 
PHONE.' (401) eT«.eMo 



410 EAST PLANZ ROAD TELEPHONB 1806) B31-3S38 
P. 0. BOX 4168 BAKERaFIELO. CALIFORNIA 93367 




rnn Pri ^r""''*"'"*^"'' 

ADonnfi nnHvar«ifv of California 

cm l> STATE 



IRRIGATION SYSTEM QUOTATION NS 14522 



Fax # 

■H.OK.P17U7873B66 



DAT6_Il-18-88 




66 



Ea 



Pierce i Mile wheellines complete w/64" wheela 



@ 18 ga. sprinkler apaclng g 40 w/4";20' supply 




lOtBA ^ — — • ■ 

Prices on wheellines include deliver & inat aUatJon. Pric.a on au^Hlin 



are ju3t delivered. Prices aubject to change wo/i ot^fiNC 



ABOVE QUOTATION ACrgPTBD AS OWOtH tet 



Dellvtry 
inatruetion*. 



Addrtta- 



Cuctomar 
P. 0. No. 




TOTAL 



SALM TAX 



PAID WITH 
ORDOI 



■ALANCt 
OWINQ 



'"'^n!::iAr,»M, AR. FOB SOU>^e AND SUaJ^CT TO CHANGE WITH OUT NOTICE. SEE REvE«« S.D. .OR WA.,UNTV. CONOmONS 01 
ALL 0UOTAT_^N8_AM F O B SOUJCe. ANB au~^^ ^^^ r>BCir.P r.QPY 



^I^TSl^?^(5i;?A^^ANVc"6NbmONsVi^^^^^^ 



OFFICE COPY 




P00001900